文档介绍：Philips Semiconductors
RF transmitting transistor and
Transmitting transistor design
power amplifier fundamentals
1 TRANSMITTING TRANSISTOR DESIGN transistors are suitable, see panel, and Philips
Semiconductors’ portfolio includes both types. Their
Die technology and design relative merits are summarized later in this section. First,
A transmitting transistor has to deliver high power at high however, let’s look at the basic aspects of design that
frequency (>1 MHz). This means that a large transistor die contribute to the reliability and high-performance of a
with a fine structure is required. Bipolar and MOS modern RF transmitting transistor.
TRANSISTOR FABRICATION
As is well-known, most transistors are fabricated from silicon wafers (5" dia. or larger, and about mm thick)
in a multi-stage batch process that involves precise, localized doping of an epitaxial layer grown on the silicon
substrate to form the different transistor regions. The main process steps for fabricating bipolar transistors are
shown here as a reminder. MOS transistors are fabricated using similar techniques. Though semiconductor
manufacturers have many processes available to meet mercial and technical specifications, they all
are based on the principles outlined below.
1. Silicon wafer
2. Oxidize to form oxide layer
3. Apply photosensitive layer
4. Expose through high-resolution mask
5. Develop photosensitive layer handbook, full pagewidth
6. Etch base window through oxide layer
7. Remove remaining photosensitive layer
8. Diffuse or ion-implant the base
9. Oxidize base window
10. Expose emitter window 1 6 11
11. Etch emitter window through oxide layer
12. Remove remaining photosensitive layer
13. Diffuse or ion-implant the emitter
14. Create metallization window
15. Metallize base and emitter regions
16. Polish and metallize bottom (collector).
2 7 12
3 8 13
mask
4 9 14
mask
5 10 15
Base Emitter
Silicon oxide