Claims
- 1. A high frequency digital switching transistor formed on a silicon substrate having a gate insulator layer of approximately 17-21 angstroms in thickness which is formed of substantially only silicon oxynitride.
- 2. A high frequency digital switching transistor as defined in claim 1 which is part of a hybrid integrated circuit which also includes an analog linear transistor formed on the silicon substrate, the analog linear transistor having a gate insulator layer of at least 60 angstroms in thickness which is formed of silicon dioxide.
- 3. A high frequency digital switching transistor as defined in claim 1 in which the gate insulator layer is formed by a process comprising the steps of:
implanting nitrogen atoms into silicon substrate; oxidizing the nitrogen and silicon to form a layer of the silicon oxynitride; forming an outer layer of silicon dioxide as a part of forming the silicon oxynitride layer; removing the outer layer of silicon dioxide from the silicon oxynitride layer to leave a remaining layer of substantially-only silicon oxynitride; and forming the gate insulator from the remaining layer of substantially-only silicon oxynitride.
- 4. A high frequency digital switching transistor as defined in claim 3 which is part of a hybrid integrated circuit that also includes an analog linear transistor which is formed on the silicon substrate and which has a gate insulator which is formed by steps occurring simultaneously with at least some of those steps used in fabricating the gate insulator of the the digital transistor, the simultaneously occurring steps including:
oxidizing a relatively thick layer of silicon dioxide into the silicon substrate to form the analog transistor gate insulator simultaneously with oxidizing the nitrogen and silicon to form a layer of the silicon oxynitride; and removing an upper portion of the relatively thick initial layer of silicon dioxide for the analog transistor gate insulator simultaneously with removing the outer layer of silicon dioxide from the silicon oxynitride layer.
CROSS-REFERENCE TO RELATED INVENTIONS
[0001] This invention is a division of U.S. application Ser. No. 09/724,225 filed Nov. 28, 2000, filed by the inventors herein.
Divisions (1)
|
Number |
Date |
Country |
Parent |
09724225 |
Nov 2000 |
US |
Child |
10304631 |
Nov 2002 |
US |