(19)
(11)EP 2 251 681 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
29.07.2020 Bulletin 2020/31

(21)Application number: 09714045.3

(22)Date of filing:  24.02.2009
(51)Int. Cl.: 
G01N 27/00  (2006.01)
G01N 29/036  (2006.01)
G01N 29/02  (2006.01)
(86)International application number:
PCT/KR2009/000868
(87)International publication number:
WO 2009/107965 (03.09.2009 Gazette  2009/36)

(54)

PHYSICAL/BIOCHEMICAL SENSOR EMPLOYING AN ARRAY OF PIEZOELECTRIC MICRO-CANTILEVER RESONATORS OF SEVERAL SIZES, AND A PRODUCTION METHOD THEREFOR

PHYSIKALISCHER/BIOCHEMISCHER SENSOR MIT EINEM ARRAY AUS PIEZOELEKTRISCHEN MIKRO-CANTILEVER-RESONATOREN VERSCHIEDENER GRÖSSE SOWIE VERFAHREN ZU SEINER HERSTELLUNG

CAPTEUR PHYSIQUE/BIOCHIMIQUE UTILISANT UN RÉSEAU DE RÉSONATEURS A MICRO-PORTE-A-FAUX PIÉZOÉLECTRIQUES DE PLUSIEURS DIMENSIONS, ET PROCÉDÉ DE PRODUCTION DE CELUI-CI


(84)Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK TR

(30)Priority: 29.02.2008 KR 20080019031

(43)Date of publication of application:
17.11.2010 Bulletin 2010/46

(73)Proprietor: Sungkyunkwan University Foundation for Corporate Collaboration
Gyeong-gi do 440-746 (KR)

(72)Inventors:
  • LEE, Jai Chan
    Seoul 137-775 (KR)
  • SHIN, Sang Hun
    Suwon-si Gyeonggi-do 440-330 (KR)

(74)Representative: Brann AB 
P.O. Box 3690 Drottninggatan 27
103 59 Stockholm
103 59 Stockholm (SE)


(56)References cited: : 
JP-A- 1 209 354
KR-A- 20050 095 964
KR-B1- 100 583 233
US-A1- 2007 023 851
JP-A- 4 370 742
KR-A- 20050 096 469
US-A- 5 856 722
US-A1- 2007 145 966
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    [Technical Field]



    [0001] The present invention relates to a physical/biochemical sensor using a multisized piezoelectric microcantilever resonator array and a manufacturing method thereof; and, more particularly, the present invent relates to a physical/biochemical sensor using a multisized piezoelectric microcantilever resonator array, which enables a simultaneous and quantitative analysis of both an surface stress change effect and a mass loading effect due to adsorption of a sensing-target material by measuring a resonant frequency shift obtained during a sensing process, and thus can be used for analyzing a sensing-target material in various application fields, and to a manufacturing method thereof.

    [Background Art]



    [0002] The ultimate goal of the modern scientific technology development is to improve the quality of human life. Especially, in the fields of biotechnology and environmental engineering, various researches have been actively conducted to predict a disease or diagnose a disease at an early stage prior to starting the treatment and to efficiently control various kinds of problems that may directly affect the human life span.

    [0003] As examples of such research trend, the research and developments have been made for a human body biomarker for detecting a harmful substance or diagnosing a disease, and a super-microscopic precision sensor system for detecting the presence of a sensing-target material such as a pathogenic organism, or the occurrence of a certain biochemical reaction in a fast and simple manner. When a biochemical substance and a harmful pollutant to be sensed, which exist in air, aquatic environment or the human body, are present in a very low concentration, there are many drawbacks to be overcome in order to analyze them by a conventional analysis method. That is, a high-cost and large-scale analyzing apparatus is required for extraction, concentration and analysis of a sample and it takes a great amount of time for pre-treating a sample. In order to analyze the sensing-target material on a real-time basis without having to perform the sample pre-process such as the sample extraction and concentration, the sensitivity of a sensor device used in the analysis needs to be high enough to detect a mass at a single-molecule level.

    [0004] As one of such sensors, a microcantilever integrated with a piezoelectric driving component can be self-driven by an AC electric field and can quickly read a great change in an AC signal caused by a piezoelectric effect at a resonant frequency point through an electric measurement. Research reports related to this have been already reported by many other researchers, including the patent applications and the journals filed and published by the present inventors' research group.

    [0005] In an actual application for detecting a sensing-target material, a microcantilever resonator sensor operated with a resonant frequency using a piezoelectric mechanism or another driving principle outputs a sensing signal in the form of a resonant frequency shift of a cantilever with respect to a mass change on a cantilever surface that occurs during a sensing process, and analyzes it to give a result. To implement a wider range of application and a more accurate analysis, it is desirable to use an array-type device having an array of a plurality of cantilevers rather than to use a single cantilever. Meanwhile, the resonant frequency of the cantilever decreases or increases due to a change in the surface stress as well as due to a change in the surface mass during the sensing process. However, when a single cantilever or an array-type device having an array of a plurality of same-sized cantilevers is used, a mass loading effect and a surface stress change effect occurring during the sensing process cannot be distinguished when a resonant frequency change as a sensing signal is analyzed. Although the degree of mechanical bending of the cantilever due to the surface stress change can be measured and analyzed by an optical method, it is difficult to discriminately analyze the mass loading effect and the surface stress change effect in case of using the resonant frequency shift as a primary sensing signal, since the mass loading effect and the surface stress effect are simultaneously exerted.

    [0006] US 2007/023851 A1 discloses a MEMS pixel sensor (MPS) as part of a sensor array. The individual MPS may have different mechanical characteristics resulting in a broadband response. The device can be used for detection of for example DNA, protein, antibody interactions.

    [0007] KR 20050096469A discloses a generally applicable method for fabricating a physical/biochemical sensor comprising a piezoelectric microcantilever resonator.

    [Disclosure of the Invention]


    [Problems to Be Solved by the Invention]



    [0008] In view of the foregoing, the present invention provides a physical/biochemical sensor using a multisized piezoelectric microcantilever resonator array, which enables a quantitative and simultaneous analysis of both a surface stress change effect and a mass loading effect induced by adsorption of a sensing-target material.

    [Means for Solving the Problems]



    [0009] In accordance with one aspect of the present invention, there is provided a physical/biochemical sensor using a multisized piezoelectric microcantilever resonator according to claim 1.

    [0010] In accordance with another aspect of the present invention, there is provided a method for manufacturing a physical/biochemical sensor according to claim 4.

    [Effect of the Invention]



    [0011] As described, a physical/biochemical senor using a multisized piezoelectric microcantilever resonator array in accordance with the present invention has an advantage in that it is capable of discriminately analyzing a surface stress change as well as a surface mass change of the sensor induced by an adsorbed sensing-target material which occurs during various sensing processes. That is, since it is feasible to rapidly respond to a concentration of an extremely small amount of a sensing-target material from the outside and thus to conduct an immediate detection via the resonant frequency shift, it has a high response speed and a high sensitivity. Further, since the effect of the surface stress change in the sensing process in addition to the increase of the surface-adsorbed mass by a biochemical reaction can be recognized, a wider range of information from the sensing results can be acquired and more accurate sensing results can be obtained.

    [0012] Moreover, when a sensor platform in accordance with the present invention is applied to a biochemical field, not only a presence or absence of a sensing-target material can be determined but also a reaction between the sensing material and the sensing-target material and a reaction behavior between the sensing-target materials can be investigated directly or indirectly.

    [0013] Meanwhile, when the sensor platform in accordance with the present invention is used as a physical sensor for measuring a thickness of a thin film in a deposition process for forming thin films of various materials instead of a conventional quartz crystal microbalance (QCM) sensor, the surface stress effect can be analyzed by electrically analyzing only a resonant frequency signal obtained from the multisized piezoelectric microcantilever resonator array, so that more accurate information upon the thickness of the deposited thin film can be obtained and also mechanical characteristics of the thin material can be simultaneously analyzed.

    [Brief Description of the Drawings]



    [0014] 

    Fig. 1 is a schematic configuration view of a physical/biochemical sensor using a multisized piezoelectric microcantilever resonator array in accordance with an embodiment of the present invention;

    Fig. 2 is a cross sectional view of the physical/biochemical sensor using the multisized piezoelectric microcantilever resonator array;

    Figs. 3A to 3E provide cross sectional state views to describe a manufacturing process of the physical/biochemical sensor using the multisized piezoelectric microcantilever resonator array;

    Figs. 4B to 4E present a plane view (top view) to describe the manufacturing process of the physical/biochemical sensor using the multisized piezoelectric microcantilever resonator array;

    Figs. 5 to 9 are graphs showing the resonant frequency shift in each of piezoelectric microcantilever resonator arrays, respectively; and

    Fig. 10 is a graph indicating a frequency shift obtained by the physical/biochemical sensor using the multisized piezoelectric microcantilever resonator array as a function of lengths of piezoelectric microcantilever resonators.


    [Explanation of Codes]



    [0015] 
    1: Piezoelectric driving thin layer 2: lower
    electrode  
    3: Upper electrode 4: Supporting layer
    5: Insulating layer 6: Silicon substrate
    7: Electrode line 8: Pad
    10: Piezoelectric microcantilever resonator  

    [Best Mode for Carrying out the Invention]



    [0016] Hereinafter, a physical/biochemical sensor using a multisized piezoelectric microcantilever resonator array and a manufacturing method thereof will be described in detail in accordance with an embodiment of the present invention with reference to the accompanying drawings.

    [0017] Fig. 1 is a schematic configuration view of the physical/biochemical sensor using the multisized piezoelectric microcantilever resonator array in accordance with the embodiment of the present invention, and Fig. 2 is a cross sectional view of the physical/biochemical sensor using the multisized piezoelectric microcantilever resonator array. Figs. 3A to 3E are cross sectional state views to describe a manufacturing process of the physical/biochemical sensor using the multisized piezoelectric microcantilever resonator array. Fig. 4 depicts plane views to describe the manufacturing process of the physical/biochemical sensor using the multisized piezoelectric microcantilever resonator array, and Figs. 5 to 9 are graphs showing a resonant frequency shift of each piezoelectric microcantilever resonator array. Fig. 10 is a graph indicating a frequency shift obtained by the physical/biochemical sensor using the multisized piezoelectric microcantilever resonator array as a function of lengths of piezoelectric microcantilever resonators.

    [0018] As illustrated, the physical/biochemical sensor using the multisized piezoelectric microcantilever resonator array has a configuration in which a plurality of piezoelectric microcantilever resonators 10 having different sizes are arrayed. That is, the piezoelectric microcantilever resonators 10 are arrayed in a manner that they are 2-dimensionally and gradually scaled down.

    [0019] Each of the piezoelectric microcantilever resonators 10, constituting the microcantilever resonator array and having the different sizes, includes: a supporting layer 4 formed on a silicon substrate 6; a lower electrode 3 formed on the supporting layer 4 in a predetermined size; a piezoelectric driving thin layer 1 for piezoelectric driving, formed on the lower electrode 3; an insulating layer 5 for inter-electrode insulation, formed on the lower electrode 2 and on a part of the piezoelectric driving thin layer 1; an upper electrode 3 formed on the insulating layer 5 and on the piezoelectric driving thin layer 1; and an electrode line 7 and a pad 8 connected to the upper electrode and the lower electrode so as to apply an electric field for driving a device. Here, the supporting layers 4 of the respective resonators 10 are arrayed in a manner that their lengths are gradually reduced.

    [0020] The supporting layers 4 includes a plurality of a silicon nitride layer cantilevers formed on the silicon substrate 6, which are arrayed in a manner that their lengths are gradually reduced, and silicon oxide layers formed on each of the silicon nitride layer cantilevers.

    [0021] In the piezoelectric microcantilever resonator 10, a piezoelectric material is used as a thin layer material for piezoelectric driving. Such piezoelectric materials are what use a principle that a potential difference (voltage) is generated when a pressure is applied to a certain crystal while a physical displacement occurs when a potential difference (voltage) is reversely applied thereto. The piezoelectric material is mainly classified into nitrides and oxides. Aluminum nitride (AlN) is typically used as the nitride, and, as the oxide, zinc oxide (ZnO) which is a piezoelectric material without lead, or Pb(Zr,Ti)O3 (lead zirconium titanate, hereinafter, simply referred to as PZT) which is a piezoelectric material with lead is typically used.

    [0022] The insulating layer 5 is formed by a photolithography process using a patternable material such as photosensitive polyimides. A fundamental resonant frequency and a resonant frequency shift of a piezoelectric driving device are indicated by a variation of an electric signal such as complex impedance, which is measured by an impedance analyzer incorporated in a sensor module. Thus, the physical/biomechanical sensor, using the multisized piezoelectric microcantilever resonator array which includes the plurality of piezoelectric microcantilever resonators 10 arrayed with being 2-dimensionally and gradually scaled down, measures a resonant frequency value of the device by detecting frequency using an oscillator and a frequency counter implemented on a circuit, and determines a presence or absence of a sensing-target material by measuring and analyzing all resonant frequencies of the piezoelectric microcantilevers included in the multisized microcantilever resonator array 10, wherein the resonant frequencies are changed by a reaction between a sensing material layer of the sensor and the sensing-target material after the device is exposed to a measuring environment.

    [0023] The fundamental resonant frequency value of the piezoelectric microcantilever resonator 10 in the present invention increases in reciprocal proportion to the square of a device length, and excellent sensitivity can be attained in comparison to the case that a high resonant frequency value is obtained by reducing the size of the device. Especially, in order to detect a microscopic material having a molecule-level mass, a device capable of sensing a small mass in or below a femtogram regime is required. Accordingly, among the silicon nitride layer cantilevers having various sizes which are included in the multisized piezoelectric microcantilever resonator array 10, a small silicon nitride layer cantilever showing a higher sensitivity to an increase of a surface mass which occurs during the sensing process of the sensing-target material is desirably set to have a length and a width of about 30 µm and about 10 µm, respectively.

    [0024] For example, when the piezoelectric microcantilever resonators 10 having five different sizes are integrated, the size (length, width and thickness) of each resonator is as follows.
    1. A: 240 µm (length), 80 µm (width), 2.3 µm (thickness)
    2. B: 180 µm (length), 60 µm (width), 2.3 µm (thickness)
    3. C: 120 µm (length), 40 µm (width), 2.3 µm (thickness)
    4. D: 60 µm (length), 20 µm (width), 2.3 µm (thickness)
    5. E: 30 µm (length), 10 µm (width), 2.3 µm (thickness)


    [0025] Desirably, the upper electrode, the lower electrode, the piezoelectric driving thin layer and the supporting layer (silicon nitride layer cantilever + silicon oxide layer) are designed to have thicknesses of about 0.1 µm, 0.15 µm, 0.5 µm and 1.55 µm (1.2 µm + 0.35 µm), respectively.

    [0026] Since the piezoelectric microcantilever resonator 10 having the smallest length of about 30 µm has a sufficiently large spring constant, it tends to be insensitive to a stress change on a cantilever surface which occurs in the sensing process. On the other hand, since the large piezoelectric microcantilever resonator 10 having the length of about 240 µm has a small spring constant, it is sensitive to both a surface mass increase and a surface stress change that occur in the sensing process.

    [0027] A change of the spring constant k (kTheoretical) according to the size of the microcantilever resonator 10 can be explained by the following equation.



    [0028] In the above equation, E* used to define the spring constant (kTheoretical) denotes the Young's Modulus of the microcantilever resonator 10; t, the thickness of the microcantilever resonator; w and L, the width and the length of the microcantilever resonator, respectively. In the present invention, the thicknesses of the microcantilever resonators included in the multisized microcantilever resonator array are maintained constant. Thus, the thickness t in the above equation is not considered in describing a relationship between the spring constant change and the planar size of the microcantilever resonator 10. Accordingly, the spring constant change depending on the variation of the size of the microcantilever resonator 10 is determined by a ratio (w/L3) of the width to the cube of the length of the microcantilever resonator 10. Further, when the planar size of the microcantilever resonator 10 is 2-dimensionally reduced while the ratio (L/w) of the length to the width thereof is maintained constant, it can be found that the spring constant (kTheoretical) of the microcantilever resonator 10 increases in reciprocal proportion to the square of the length.

    [0029] Among the piezoelectric microcantilever resonators 10 illustrated in the present embodiment, the largest resonator has a length eight times as long as that of the smallest one. Consequently, the smallest resonator has a spring constant of about 64 times as great as that of the largest one.

    [0030] In order to discriminately analyze a surface mass loading effect and a surface stress change effect in an application of the sensor, it may be desirable to design a length difference between the piezoelectric microcantilevers 10 to be at least three times so that the spring constants of a small microcantilever and a large microcantilever have a difference of at least 10 times.

    [0031] The manufacturing process of the physical/biochemical sensor using the multisized piezoelectric microcantilever resonator array is described as follows with reference to Figs. 3 and 4.

    [0032] The manufacturing process includes the steps of (a) depositing a silicon nitride layer cantilever on each of a top and a bottom of a silicon substrate; (b) forming a supporting layer 4 by depositing a silicon oxide layer on the upper silicon nitride layer cantilever; (c) forming a lower electrode 2 including a junction layer on the entire top surface of the silicon oxide layer; (d) forming a piezoelectric driving thin layer 1 for piezoelectric driving on the entire top surface of the lower electrode 2; (e) etching a part of the formed piezoelectric driving thin layer 1 to form a multisized piezoelectric driving thin layer material array integrated in the multisized piezoelectric microcantilever resonator array sensor; (f) etching a part of the lower electrode 2 below the multisized piezoelectric driving material array to form a multisized lower electrode array, and an electrode line 7 and a pad 8 for applying a driving voltage, integrated in the multisized piezoelectric microcantilever resonator array sensor; (g) forming an insulating layer 5 for insulating between an upper electrode and the lower electrode on a part of each of the multisized lower electrode array and the multisized piezoelectric driving thin layer material array; (h) forming a multisized upper electrode array, and an electrode line 7 and a pad 8 for applying a driving voltage, on the insulating layer 5 and on the multisized piezoelectric driving thin layer material array; (i) removing a part of the lower silicon nitride layer cantilever; (j) etching the silicon substrate 6 exposed after the step (i) ; and (k) removing a part of the upper silicon nitride layer of the device wherein the silicon substrate 6 is etched in the step (j) to thereby form a multisized piezoelectric microcantilever resonator array sensor.

    [0033] The manufacturing process may further include a step (1) of forming a sensing layer for sensing the sensing-target material after the step (k).

    [0034] The step (1) may involve depositing a gold thin film on the microcantilever surface, forming a self-assembled monolayer by using a gold-thiol reaction, and immobilizing a sensing material suitable for the sensing-target material, so as to form a sensing material layer for sensing a biomaterial. Alternatively, for an application as a chemical sensor, the step (1) may include forming a sensing material layer by inkjet-printing, spin-coating or dip-coating a solution containing a polymer material to which the sensing-target material can be bonded, on the microcantilever surface.

    [0035] Figs. 5 to 9 show resonant frequency shifts in the multisized piezoelectric microcantilever resonators 10 having five different sizes, which were obtained after a series of steps of depositing a gold thin film on a rear surface of each multisized piezoelectric microcantilever resonator 10, forming a self-assembled monolayer by a gold-alkanethiol reaction and immobilizing a human antibody by using biotin, streptavidin, and the like. The small resonator (s) has a very high resonant frequency, and its sensitivity to a loaded mass is very high. Accordingly, a frequency decrease due to the immobilization of the human antibody (IgG) was conspicuous. Meanwhile, since the large resonator(s) has a smaller fundamental resonant frequency and a lower sensitivity to a mass compared to the small one(s), the large resonator (s) showed a comparatively smaller decrease in the frequency than the results of the small size resonator(s) which were simultaneously obtained.

    [0036] Fig. 10 shows a frequency shift obtained in each of the multisized piezoelectric microcantilever resonators 10 as a function of a cantilever length, according to the embodiments depicted in Figs. 5 to 9. In Fig. 10, a graph illustrated by a line with black squares indicates a theoretical frequency shift which is expected due to a surface mass increase when the human antibody (IgG) is immobilized using the multisized piezoelectric microcantilever resonator array sensor, and a graph illustrated by a line with circles indicates a frequency shift obtained in an actual experiment.

    [0037] As can be seen from the graphs, the piezoelectric microcantilever resonator 10 having the length of about 30 µm was found to be hardly affected by a surface stress induced during the sensing process. Accordingly, in implementing multiple sizes, it is deemed to be desirable as a piezoelectric microcantilever resonator 10 having a property that a frequency shift induced by an adsorbed mass is dominant. However, it may be desirable to use a piezoelectric microcantilever resonator 10 having a smaller size and a high spring constant to be less affected by the surface stress induced during the sensing process. Meanwhile, the piezoelectric microcantilever resonator 10 having the length of 240 µm was found to be greatly affected by the surface stress, so that it is deemed to be desirable as a piezoelectric microcantilever resonator 10 having a property that a frequency shift induced by a surface stress change is dominant.

    [0038] As described above, by using the physical/biochemical sensor using the multisized piezoelectric microcantilever resonator array in accordance with the present invention, not only the information upon surface-adsorbed mass during the sensing process can be analyzed, but also the surface stress effect can be simultaneously analyzed by comparing an expected frequency shift pattern obtained from a mass sensitivity of each of the multisized piezoelectric microcantilever resonator arrays having their own sizes_with a resonant frequency shift pattern obtained in the actual sensing process. That is, more abundant information upon a biochemical reaction between the sensing material formed on the surface of the cantilever and the sensing-target material can be obtained. Therefore, the physical/biochemical sensor using the multisized piezoelectric microcantilever resonator array in accordance with the present invention is capable of quickly and accurately detecting a presence or absence of various kinds of sensing-target materials in an extremely small amount, and also capable of simultaneously and discriminately analyzing a surface stress effect when the sensing material formed on the surface of the cantilever reacts with the various kinds of sensing-target materials, thus improving an ability to discriminate between the sensing-target materials in sensing results.

    [0039] While the invention has been shown and described with reference to the above-described embodiments, the present invention is not limited thereto, and it would be understood by those skilled in the art that various changes and modification may be made without departing form the scope of the invention as claimed in the following claims. Thus, it shall be understood that all modifications and embodiments conceived from the meaning and scope of the claims are included in the scope of the present invention.


    Claims

    1. A physical/biochemical sensor having a multisized piezoelectric microcantilever resonator array, wherein a plurality of piezoelectric microcantilever resonators (10) has different sizes, wherein each of the multisized piezoelectric microcantilever resonators (10) includes:

    a silicon nitride layer cantilever formed on a silicon substrate (6);

    a silicon oxide layer formed on the silicon nitride layer cantilever;

    a lower electrode (2) formed in a preset size on the silicon oxide layer;

    a piezoelectric driving thin layer (1) for piezoelectric driving, formed on the lower electrode (2);

    an insulating layer (5) for an inter-electrode insulation, formed on the lower electrode (2) and on a part of the piezoelectric driving thin layer (1);

    an upper electrode (3) formed on the insulating layer (5) and on the piezoelectric driving thin layer (1); and

    an electrode line (7) for applying an electric field to drive a device, connected to the upper electrode (3) and the lower electrode (2), and wherein

    the cantilevers of the multisized piezoelectrical microcantilever resonator array having gradually reduced lengths, wherein the widths of the silicon nitride layer cantilevers are reduced at the same ratio as the reduction ratio of their lengths, and the thicknesses of the silicon nitride layer cantilevers are maintained constant, and wherein the longest piezoelectric microcantilever resonator (10) has a length at least three times as long as that of the shortest piezoelectric microcantilever resonator (10), so as to quantitatively and discriminately analyze a surface stress change as well as a mass change on a sensor surface induced by an adsorption of a sensing-target material during a sensing process.


     
    2. The physical/biomechanical sensor of claim 1, wherein the insulating layer (5) comprises polyimide.
     
    3. The physical/biochemical sensor of claim 1, wherein the piezoelectric driving layer (1) is formed of a piezoelectric material for piezoelectric driving in the piezoelectric microcantilever resonator (10).
     
    4. A method for fabricating a physical/biochemical sensor as claimed in any one of claims 1 to 3, the method comprising:

    (a) depositing a silicon nitride layer cantilever on each of a top and a bottom of a silicon substrate (6);

    (b) depositing a silicon oxide layer on the upper silicon nitride layer cantilever;

    (c) forming a lower electrode (2) including a junction layer on the entire surface of the silicon oxide layer;

    (d) forming a piezoelectric driving thin layer (1) for piezoelectric driving on the entire top surface of the lower electrode (2);

    (e) etching a part of the formed piezoelectric driving thin layer (1) to form a multisized piezoelectric driving thin layer material array integrated in the multisized piezoelectric microcantilever resonator array sensor;

    (f) etching a part of the lower electrode (2) below the multisized piezoelectric driving thin layer material array to form a multisized lower electrode array, and an electrode line (7) and a pad (8) for applying a driving voltage, integrated in the multisized microcantilever resonator array;

    (g) forming an insulating layer (5) for insulation between an upper electrode (3) and the lower electrode (2) on a part of the multisized lower electrode array and the multisized piezoelectric driving thin layer material array;

    (h) forming a multisized upper electrode array, and an electrode line (7) and a pad (8) for applying a driving voltage on the insulating layer (5) and on the multisized piezoelectric driving thin layer material array;

    (i) removing a part of the lower silicon nitride layer cantilever;

    (j) etching the silicon substrate (3) exposed after the step (i); and

    (k) removing a part of the upper silicon nitride layer of a device wherein the silicon substrate (3) is etched in the step (j) to form a multisized piezoelectric microcantilever resonator array sensor.


     
    5. The method of claim 4, further comprising a step (1) of forming a sensing layer for detecting a sensing-target material after the step (k).
     
    6. The method of claim 5, wherein the step (1) includes depositing a gold thin film on the microcantilever surface; forming a self-assembled monolayer by using a gold-thiol reaction; and immobilizing a sensing material suitable for the sensing-target material, so as to form a sensing material layer for detecting a biomaterial.
     
    7. The method of claim 6, wherein the step (1) includes inkjet-printing, spin-coating or dip-coating a solution containing a polymer material to which the sensing-target material can be bonded, on the microcantilever surface, for an application as a chemical sensor.
     


    Ansprüche

    1. Physischer/biochemischer Sensor mit einem piezoelektrischen Mikrobiegebalkenresonatorarray mit mehreren Größen, wobei eine Vielzahl von piezoelektrischen Mikrobiegebalkenresonatoren (10) unterschiedliche Größen aufweist, wobei jeder der piezoelektrischen Mikrobiegebalkenresonatoren (10) mit mehreren Größen beinhaltet:

    einen Siliziumnitridschichtbiegebalken, der auf einem Siliziumsubstrat (6) gebildet ist;

    eine Siliziumoxidschicht, die aus dem Siliziumnitridschichtbiegebalken gebildet ist;

    eine untere Elektrode (2), die in einer voreingestellten Größe auf der Siliziumoxidschicht gebildet ist;

    eine piezoelektrische Antriebsdünnschicht (1) für piezoelektrischen Antrieb, die auf der unteren Elektrode (2) gebildet ist;

    eine isolierende Schicht (5) für eine Zwischenelektrodenisolierung, die auf der unteren Elektrode (2) und auf einem Teil der piezoelektrischen Antriebsdünnschicht (1) gebildet ist;

    eine obere Elektrode (3), die auf der isolierenden Schicht (5) und auf der piezoelektrischen Antriebsdünnschicht (1) gebildet ist; und

    eine Elektrodenleitung (7) zum Anlegen eines elektrischen Felds, um eine Vorrichtung anzutreiben, die mit der oberen Elektrode (3) und der unteren Elektrode (2) verbunden ist, und wobei

    die Biegebalken des piezoelektrischen Mikrobiegebalkenresonatorarrays schrittweise reduzierte Längen aufweisen, wobei die Breiten der Siliziumnitridschichtbiegebalken bei demselben Verhältnis wie dem Reduktionsverhältnis ihrer Längen reduziert sind und die Dicken der Siliziumnitridschichtbiegebalken konstant beibehalten sind und wobei der längste piezoelektrische Mikrobiegebalkenresonator (10) eine Länge mindestens dreimal so lang wie die des kürzesten piezoelektrischen Mikrobiegebalkenresonators (10) aufweist, um eine Oberflächenspannungsänderung wie auch Masseänderung auf einer Sensoroberfläche, die durch eine Adsorption eines Erfassungszielmaterials während eines Erfassungsprozesses herbeigeführt wird, quantitativ und unterscheidend zu analysieren.


     
    2. Physischer/biomechanischer Sensor nach Anspruch 1, wobei die isolierende Schicht (5) Polyimid umfasst.
     
    3. Physischer/biochemischer Sensor nach Anspruch 1, wobei die piezoelektrische Antriebsschicht (1) aus einem piezoelektrischen Material für piezoelektrischen Antrieb in dem piezoelektrischen Mikrobiegebalkenresonator (10) gebildet ist.
     
    4. Verfahren zur Fertigung eines physischen/biochemischen Sensors nach einem der Ansprüche 1 bis 3, wobei das Verfahren umfasst:

    (a) Abscheiden einer Slliziumnitridschichtbiegebalkens sowohl an einer Oberseite als auch einem Boden eines Siliziumsubstrats (6);

    (b) Abscheiden einer Siliziumoxidschicht an dem oberen Siliziumntiridschichtbiegebalken;

    (c) Bilden einer unteren Elektrode (2), die eine Verbindungsschicht an der gesamten Oberfläche der Siliziumoxidschicht beinhaltet;

    (d) Bilden einer piezoelektrischen Antriebsdünnschicht (1) für piezoelektrischen Antrieb an der gesamten Oberseitenoberfläche der unteren Elektrode (2);

    (e) Ätzen eines Teils der gebildeten piezoelektrischen Antriebsdünnschicht (1), um ein piezoelektrisches Antriebsdünnschichtmaterialarray mit mehreren Größen zu bilden, das in dem piezoelektrischen Mikrobiegebalkenresonatorarraysensor mit mehreren Größen integriert ist;

    (f) Ätzen eines Teils der unteren Elektrode (2) unter dem piezoelektrischen Antriebsdünnschichtmaterialarray mit mehreren Größen, um ein unteres Elektrodenarray mit mehreren Größen und eine Elektrodenleitung (7) und ein Kontaktfeld (8) zum Anlegen einer Antriebsspannung zu bilden, die in dem Mikrobiegebalkenresonatorarray mit mehreren Größen integriert sind;

    (g) Bilden einer isolierenden Schicht (5) zur Isolierung zwischen einer oberen Elektrode (3) und der unteren Elektrode (2) an einem Teil des unteren Elektrodenarrays mit mehreren Größen und dem piezoelektrischen Antriebsdünnschichtmaterialarray mit mehreren Größen;

    (h) Bilden eines oberen Elektrodenarrays mit mehreren Größen und einer Elektrodenleitung (7) und eines Kontaktfelds (8) zum Anlegen einer Antriebsspannung an der isolierenden Schicht (5) und an dem piezoelektrischen Antriebsdünnschichtmaterialarray mit mehreren Größen;

    (i) Entfernen eines Teils des unteren Siliziumnitridschichtbiegebalkens;

    (j) Ätzen des Siliziumsubstrats (3), das nach dem Schritt (i) freigelegt ist; und

    (k) Entfernen eines Teils der oberen Siliziumnitridschicht einer Vorrichtung, wobei das Siliziumsubstrat (3) in dem Schritt (j) geätzt wird, um einen piezoelektrischen Mikrobiegebalkenresonatorarraysensor mit mehreren Größen zu bilden.


     
    5. Verfahren nach Anspruch 4, weiter umfassend einen Schritt (I) zum Bilden einer Erfassungsschicht zum Detektieren eines Erfassungszielmaterials nach dem Schritt (k).
     
    6. Verfahren nach Anspruch 5, wobei der Schritt (I) Abscheiden eines Golddünnfilms an der Mikrobiegebalkenoberfläche beinhaltet; Bilden einer selbstorganisierten Monoschicht, indem eine Gold-Thiol Reaktion verwendet wird; und Immobilisieren eines Erfassungsmaterials, das für das Erfassungszielmaterial geeignet ist, um eine Erfassungsmaterialschicht zum Detektieren eines Biomaterials zu bilden.
     
    7. Verfahren nach Anspruch 6, wobei der Schritt (I) Tintenstrahldrucken, Rotationsbeschichtung oder Tauchbeschichtung einer Lösung, die ein Polymermaterial, an das das Erfassungszielmaterial gebondet werden kann, an der Mikrobiegebalkenoberfläche enthält, für eine Anwendung als einen chemischen Sensor beinhaltet.
     


    Revendications

    1. Capteur physique/biochimique ayant un réseau de résonateurs à micro-porte-à-faux piézoélectriques de plusieurs tailles, dans lequel une pluralité de résonateurs à micro-porte-à-faux piézoélectriques (10) ont des tailles différentes, dans lequel chacun des résonateurs à micro-porte-à-faux piézoélectriques de plusieurs tailles (10) inclut :

    un porte-à-faux à couche de nitrure de silicium formé sur un substrat de silicium (6) ;

    une couche d'oxyde de silicium formée sur le porte-à-faux à couche de nitrure de silicium ;

    une électrode inférieure (2) formée à une taille préréglée sur la couche d'oxyde de silicium ;

    une couche mince d'entraînement piézoélectrique (1) pour un entraînement piézoélectrique, formée sur l'électrode inférieure (2) ;

    une couche isolante (5) pour une isolation entre électrodes, formée sur l'électrode inférieure (2) et sur une partie de la couche mince d'entraînement piézoélectrique (1) ;

    une électrode supérieure (3) formée sur la couche isolante (5) et sur la couche mince d'entraînement piézoélectrique (1) ; et

    une ligne d'électrodes (7) pour appliquer un champ électrique afin d'entraîner un dispositif, reliée à l'électrode supérieure (3) et à l'électrode inférieure (2), et dans lequel

    les porte-à-faux du réseau de résonateurs à micro-porte-à-faux piézoélectriques de plusieurs tailles ont des longueurs progressivement réduites, dans lequel les largeurs des porte-à-faux à couche de nitrure de silicium sont réduites au même taux que le taux de réduction de leurs longueurs, et les épaisseurs des porte-à-faux à couche de nitrure de silicium sont maintenues constantes, et dans lequel le résonateur à micro-porte-à-faux piézoélectrique (10) le plus long a une longueur au moins trois fois supérieure à celle du résonateur à micro-porte-à-faux piézo-électrique (10) le plus court, de manière à analyser quantitativement et distinctement un changement de contrainte de surface ainsi qu'un changement de masse sur une surface de capteur induite par une adsorption d'une matière cible de détection au cours d'un processus de détection.


     
    2. Capteur physique/biochimique selon la revendication 1, dans lequel la couche isolante (5) comprend un polyimide.
     
    3. Capteur physique/biochimique selon la revendication 1, dans lequel la couche d'entraînement piézoélectrique (1) est formée d'une matière piézoélectrique pour un entraînement piézoélectrique dans le résonateur à micro-porte-à-faux piézoélectrique (10).
     
    4. Procédé de fabrication d'un capteur physique/biochimique selon l'une quelconque des revendications 1 à 3, le procédé comprenant :

    (a) le dépôt d'un porte-à-faux à couche de nitrure de silicium sur chacun d'un sommet et d'un fond d'un substrat de silicium (6) ;

    (b) le dépôt d'une couche d'oxyde de silicium sur le porte-à-faux à couche de nitrure de silicium supérieur ;

    (c) la formation d'une électrode inférieure (2) incluant une couche de jonction sur la surface complète de la couche d'oxyde de silicium ;

    (d) la formation d'une couche mince d'entraînement piézoélectrique (1) pour un entraînement piézoélectrique sur la surface de sommet complète de l'électrode inférieure (2) ;

    (e) la gravure d'une partie de la couche mince d'entraînement piézoélectrique (1) formée pour former un réseau de matières de couche mince d'entraînement piézoélectrique de plusieurs tailles intégré dans le capteur de réseau de résonateurs à micro-porte-à-faux piézoélectriques de plusieurs tailles ;

    (f) la gravure d'une partie de l'électrode inférieure (2) au-dessous du réseau de matières de couche mince d'entraînement piézoélectrique de plusieurs tailles pour former un réseau d'électrodes inférieures de plusieurs tailles, et une ligne d'électrodes (7) et un plot (8) pour appliquer une tension d'entraînement, intégrés dans le réseau de résonateurs à micro-porte-à-faux de plusieurs tailles ;

    (g) la formation d'une couche isolante (5) pour une isolation entre une électrode supérieure (3) et l'électrode inférieure (2) sur une partie du réseau d'électrodes inférieures de plusieurs tailles et le réseau de matières de couche mince d'entraînement piézoélectrique de plusieurs tailles ;

    (h) la formation d'un réseau d'électrodes supérieures de plusieurs tailles, et d'une ligne d'électrodes (7) et d'un plot (8) pour appliquer une tension d'entraînement sur la couche isolante (5) et sur le réseau de matières de couche mince d'entraînement piézoélectrique de plusieurs tailles ;

    (i) le retrait d'une partie du porte-à-faux à couche de nitrure de silicium inférieur ;

    (j) la gravure du substrat de silicium (3) exposé après l'étape (i) ; et

    (k) le retrait d'une partie de la couche de nitrure de silicium supérieure d'un dispositif dans lequel le substrat de silicium (3) est gravé à l'étape (j) pour former un capteur de réseau de résonateurs à micro-porte-à-faux piézoélectriques de plusieurs tailles.


     
    5. Procédé selon la revendication 4, comprenant en outre une étape (1) de formation d'une couche de détection pour détecter une matière cible de détection après l'étape (k).
     
    6. Procédé selon la revendication 5, dans lequel l'étape (1) inclut le dépôt d'une pellicule mince d'or sur la surface de micro-porte-à-faux; la formation d'une monocouche auto-assemblée par l'utilisation d'une réaction or-thiol ; et l'immobilisation d'une matière de détection appropriée pour la matière cible de détection, de manière à former une couche de matière de détection pour détecter une biomatière.
     
    7. Procédé selon la revendication 6, dans lequel l'étape (1) inclut l'impression à jet d'encre, le revêtement par centrifugation ou le revêtement par immersion d'une solution contenant une matière polymère à laquelle la matière cible de détection peut être liée, sur la surface de micro-porte-à-faux, pour une application en tant qu'un capteur chimique.
     




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    REFERENCES CITED IN THE DESCRIPTION



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    Patent documents cited in the description