關於電阻的設計

squirrel316

在CMOS製程中
7 P$ x/ J7 W  e大致上可以知道說阻值等於sheet resistance*(L/W)
& b, a2 R' Q8 e& u7 j0 Z不過我有個問題就是L跟W值的選取
假設我要讓L/W=2
2 u1 z0 m& Q8 j! L, Q# @我可以有很多種選擇 像是2u/1u 4u/2u ...等
" A" Q+ X# J& g' z% X那請問一下這幾種選擇除了雜散電容造成的影響之外
還會有什麼影響
3 V0 {$ i+ C7 Y& q謝謝指教

seanyang1337

Dear squirrel316,
Basicly, the W should big enought and has a low bond(usually 2u for above 0.35um).
If you using too small scale like 1um, the accuracy will be very poor.
And it should be considered the eatch value.
As a reference, the foundry resistor test key, was measured by 10u/10u or larger.