關於電阻的設計

squirrel316

在CMOS製程中
, U+ G; h0 T; J6 M9 q- v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
$ T1 Q6 b  i+ Q! I+ ~4 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
+ C$ K& w) q! f2 m. S那請問一下這幾種選擇除了雜散電容造成的影響之外
# q3 }2 p1 m8 R7 l4 a2 {還會有什麼影響
4 L9 s* W% T4 N# X謝謝指教

seanyang1337

Dear squirrel316,
9 Y& I0 U" M/ ~, @* e2 XBasicly, the W should big enought and has a low bond(usually 2u for above 0.35um).
, C* Z) M. h* r6 Q4 ~If you using too small scale like 1um, the accuracy will be very poor.
And it should be considered the eatch value.
9 A6 ~5 v7 q8 ?& C' J& g0 KAs a reference, the foundry resistor test key, was measured by 10u/10u or larger.