Did You Know...
...that in 1800 ether was first used by partyers as a fun diversion? Sniffing the gas led to hilarious and raucous laughter as people watched each other become more and more intoxicated and silly. Several doctors independently realized the value ether would have to anesthetize surgery patients. Of those who claimed rights to the "discovery," none had a happy ending. One had a seizure and died defending his rights. Another spent his life in an asylum because he had been denied acclaim. A third became addicted to chloroform and, in a New York City jail, he soaked a cloth in the drug, severed an artery and bled to death.
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US Patent 5856697 - Integrated dual layer emitter mask and emitter trench for BiCMOS processes
Estimated Patent Expiration Date:
July 14, 2017Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.AbstractA new method of isolating a polysilicon emitter from the base region of a bipolar transistor, trenching the polysilicon emitter into the semiconductor substrate, and maintaining a consistent base width of a bipolar transistor independent of variations in emitter mask thicknesses is disclosed. The polysilicon emitter isolation provides for better electrical breakdown characteristics between the emitter and the base by protecting the dielectric layer between the polysilicon emitter and base regions from defects and contamination associated with the BiCMOS manufacturing environment. The polysilicon emitter is trenched into the semiconductor substrate in order to reduce transistor operation problems associated with hot electron injection. Consistent base widths improve transistor performance uniformity thereby improving manufacturability and reliability.Other References
| InventorsApplicationNo. 895270 filed on 07/14/1997US Classes:257/378, Combined with bipolar transistor257/370, Combined with bipolar transistor257/E21.696Bipolar and MOS technologies (EPO)Field of Search257/378Combined with bipolar transistorExaminersPrimary: Meier, Stephen D.Attorney, Agent or FirmUS Patent References4435898, Method for making a base etched transistor integrated circuitIssued on: 03/13/1984 Inventor: Gaur , et al.5132234, Method of producing a bipolar CMOS device Issued on: 07/21/1992 Inventor: Kim, et al.5175606, Reverse self-aligned BiMOS transistor integrated circuit Issued on: 12/29/1992 Inventor: Tsai, et al.5192992, BICMOS device and manufacturing method thereof Issued on: 03/09/1993 Inventor: Kim, et al.5196356, Method for manufacturing BICMOS devices Issued on: 03/23/1993 Inventor: Won, et al.5198372, Method for making a shallow junction bipolar transistor and transistor formed thereby Issued on: 03/30/1993 Inventor: Verret5204277, Method of forming bipolar transistor having substrate to polysilicon extrinsic base contact Issued on: 04/20/1993 Inventor: Somero, et al.5213989, Method for forming a grown bipolar electrode contact using a sidewall seed Issued on: 05/25/1993 Inventor: Fitch, et al.5319235Monolithic IC formed of a CCD, CMOS and a bipolar element Issued on: 06/07/1994 Inventor: Kihara, et al. Foreign Patent References
International ClassesH01L 029/76H01L 029/94 H01L 031/062 H01L 031/113 |
