EP 0000326 B1 19800917 - METHOD OF FORMING VERY SMALL IMPURITY REGIONS IN A SEMICONDUCTOR SUBSTRATE
Title (en)
METHOD OF FORMING VERY SMALL IMPURITY REGIONS IN A SEMICONDUCTOR SUBSTRATE
Publication
Application
Priority
US 81482977 A 19770712
Abstract (en)
[origin: US4131497A] A method of forming extremely small impurity regions within other impurity regions without the need for providing critical masks. In the preferred embodiment this is achieved by forming an undercut band within masking layers atop a substrate to define a first impurity region, such as the base region of a bipolar transistor. After this region is formed by the introduction of impurities, the undercut is filled-in by a chemical vapor deposition process. A blocking mask may then be used for the formation of the second impurity region, in this case the emitter, within the first region. The window of the second region is defined by the filled-in band, thereby insuring a selected distance between the peripheries of said first and second impurity regions. The same mask may also be used to form other self-aligned regions with the first region.
IPC 1-7
IPC 8 full level
H01L 29/73 (2006.01); H01L 21/033 (2006.01); H01L 21/31 (2006.01); H01L 21/314 (2006.01); H01L 21/331 (2006.01); H01L 21/8222 (2006.01)
CPC (source: EP US)
H01L 21/0214 (2013.01 - EP US); H01L 21/02164 (2013.01 - EP US); H01L 21/0217 (2013.01 - EP US); H01L 21/022 (2013.01 - EP US); H01L 21/033 (2013.01 - EP US); H01L 21/3144 (2016.02 - US); H01L 21/8222 (2013.01 - EP US); H01L 21/02266 (2013.01 - EP US); H01L 21/02271 (2013.01 - EP US)
Designated contracting state (EPC)
DE FR GB
DOCDB simple family (publication)
EP 0000326 A1 19790124; EP 0000326 B1 19800917; DE 2860161 D1 19801218; JP S5419677 A 19790214; JP S6138623 B2 19860830; US 4131497 A 19781226
DOCDB simple family (application)
EP 78100081 A 19780602; DE 2860161 T 19780602; JP 7662378 A 19780626; US 81482977 A 19770712