Ion-Implanted Intrinsic Base for Integrated Circuit Transistors
Original Publication Date: 1985-Jan-01
Included in the Prior Art Database: 2005-Feb-18
The process proposed here uses ion-implantation for the base region of integrated circuit transistors to improve yield, gain control, and leakage currents. Conventional processing can be followed up to and including base photoresist. The intrinsic base can then be fabricated as follows: 1. Grow base-screen oxide. 2. Ion implant base, B+ species. 3. Base anneal. 4. Strip base screen oxide. 5. Reoxidize base. The emitter sidewall is formed as follows: 6. Deposit Si3N4 (nitride). 7. Deposit CVD (chemical vapor deposited) oxide. 8. Reactive ion etch oxide/nitride layers to form emitter sidewalls. 9. Wet etch remaining oxide. 10. Grow emitter screen oxide and final base redistribution.