關於電阻的設計

squirrel316

在CMOS製程中
# V1 f' x0 w- R8 G! ~大致上可以知道說阻值等於sheet resistance*(L/W)
* {7 B7 V0 p; z# j' f不過我有個問題就是L跟W值的選取
1 A& k# S$ D0 Z7 t1 O) t: A假設我要讓L/W=2
我可以有很多種選擇 像是2u/1u 4u/2u ...等
9 u! Z0 H: v: k( d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
& i7 m& u4 p/ X: b& o! m謝謝指教

seanyang1337

Dear squirrel316,
" z& J3 M2 H9 Y6 {7 @) y# QBasicly, the W should big enought and has a low bond(usually 2u for above 0.35um).
7 R; _1 s9 G. m! @, QIf you using too small scale like 1um, the accuracy will be very poor.
( G9 ?- r8 B1 ]" |; uAnd it should be considered the eatch value.
2 o: h) K  d/ ]2 @4 [) GAs a reference, the foundry resistor test key, was measured by 10u/10u or larger.