關於電阻的設計

squirrel316

在CMOS製程中
大致上可以知道說阻值等於sheet resistance*(L/W)
$ \/ d7 P/ R! V: O6 u. _不過我有個問題就是L跟W值的選取
假設我要讓L/W=2
8 [5 B9 t; r/ W# X) l8 }我可以有很多種選擇 像是2u/1u 4u/2u ...等
那請問一下這幾種選擇除了雜散電容造成的影響之外
- G' D; i$ N/ w% J9 ?還會有什麼影響
謝謝指教

seanyang1337

Dear squirrel316,
) W; w& q& e8 v$ `( U2 W% O  iBasicly, the W should big enought and has a low bond(usually 2u for above 0.35um).
; j( M4 ]1 C; U: x; k0 z: O0 P, m# _If you using too small scale like 1um, the accuracy will be very poor.
And it should be considered the eatch value.
# d4 H2 S) q5 V$ EAs a reference, the foundry resistor test key, was measured by 10u/10u or larger.