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)
不過我有個問題就是L跟W值的選取
假設我要讓L/W=2
- t2 ?1 `% i! {0 e我可以有很多種選擇 像是2u/1u 4u/2u ...等
! C# W7 m2 q( u, ?$ g; m那請問一下這幾種選擇除了雜散電容造成的影響之外
5 h& L# u! l7 V9 C- {6 h還會有什麼影響
; ~4 g6 b0 P) X' m7 m, R; L* O謝謝指教

seanyang1337

Dear squirrel316,
! a" g8 s2 `) HBasicly, 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.