Method of making bipolar transistor having amorphous silicon contact as emitter diffusion source
US5670394A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 3, 1994 |
| Grant date | Sep 23, 1997 |
| Priority date | — |
| Expiry date | Oct 3, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/011
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The present invention teaches a method for fabricating a bipolar junction transistor ("BJT") from a semiconductor substrate having a base region, wherein the BJT comprises an increased Early voltage. The method initially comprises the step of forming a patterned interlevel dielectric layer superjacent the substrate such that a segment of the substrate is exposed. Subsequently, a contact comprising a material having a grain size smaller than polycrystalline silicon is formed superjacent the patterned interlevel dielectric layer and the segment of the substrate exposed. The contact is then implanted with a dopant. Once implanted, the substrate is annealed to enable the dopant to diffuse from the contact into the base region impeded by the grain size to form an emitter region and thereby increase the Early voltage of the bipolar junction transistor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.