Global Patent Index - EP 2668312 B8

EP 2668312 B8 20191225 - VAPOUR ETCH OF SILICON DIOXIDE WITH IMPROVED SELECTIVITY

Title (en)

VAPOUR ETCH OF SILICON DIOXIDE WITH IMPROVED SELECTIVITY

Title (de)

DAMPFÄTZUNG VON SILICIUMDIOXID MIT VERBESSERTER SELEKTIVITÄT

Title (fr)

ATTAQUE EN PHASE VAPEUR DE DIOXYDE DE SILICIUM AVEC SÉLECTIVITÉ AMÉLIORÉE

Publication

EP 2668312 B8 20191225 (EN)

Application

EP 12708367 A 20120124

Priority

  • GB 201101188 A 20110124
  • GB 2012050144 W 20120124

Abstract (en)

[origin: WO2012101431A1] The etching of a sacrificial silicon dioxide (SiO2) portion in a microstructure such as a microelectro-mechanical structures (MEMS) by the use an etchant gas, namely hydrogen fluoride (HF) vapour is performed with greater selectivity to other portions within the MEMS, and in particular portions of silicon nitride (Si3N4). This is achieved by the addition of a secondary non-etchant gas suitable for increase the ratio of difluoride reactive species (HF2 _ and H2F2) to monofluoride reactive species (F_, and HF) within the HF vapour. The secondary non-etchant gas may comprise a hydrogen compound gas. The ratio of difluoride reactive species (HF2 _ and H2F2) to the monofluoride reactive species (F_, and HF) within the HF vapour can also be increased by setting an etch operating temperature to 20°C or below.

IPC 8 full level

H01L 21/311 (2006.01); B81C 1/00 (2006.01)

CPC (source: EP GB KR US)

B81C 1/00 (2013.01 - KR); B81C 1/00531 (2013.01 - GB); B81C 1/00595 (2013.01 - EP US); C23F 1/44 (2013.01 - KR); H01L 21/30604 (2013.01 - US); H01L 21/30621 (2013.01 - GB); H01L 21/311 (2013.01 - KR); H01L 21/31116 (2013.01 - EP US); H01L 21/67063 (2013.01 - GB); B81C 2201/0109 (2013.01 - EP US); B81C 2201/0132 (2013.01 - EP US)

Designated contracting state (EPC)

AL AT BE BG CH CY CZ DE DK EE ES FI FR GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

DOCDB simple family (publication)

WO 2012101431 A1 20120802; CN 103328688 A 20130925; CN 103328688 B 20160323; DK 2668312 T3 20200217; EP 2668312 A1 20131204; EP 2668312 B1 20191120; EP 2668312 B8 20191225; ES 2767108 T3 20200616; GB 201101188 D0 20110309; GB 2487716 A 20120808; GB 2487716 B 20150603; JP 2014504805 A 20140224; JP 5864612 B2 20160217; KR 101863178 B1 20180531; KR 20140039163 A 20140401; US 10354884 B2 20190716; US 2014017901 A1 20140116

DOCDB simple family (application)

GB 2012050144 W 20120124; CN 201280006276 A 20120124; DK 12708367 T 20120124; EP 12708367 A 20120124; ES 12708367 T 20120124; GB 201101188 A 20110124; JP 2013549897 A 20120124; KR 20137021088 A 20120124; US 201213980638 A 20120124