關於電阻的設計

squirrel316

在CMOS製程中
( K1 l" }% t" y  [; ~1 ^& ]; Z& q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
2 r4 S+ S' ^/ g/ V$ r' w我可以有很多種選擇 像是2u/1u 4u/2u ...等
1 {1 p' ?5 Z; n" O+ ], G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
謝謝指教

seanyang1337

Dear squirrel316,
Basicly, the W should big enought and has a low bond(usually 2u for above 0.35um).
; Y% K# N+ ^+ qIf you using too small scale like 1um, the accuracy will be very poor.
And it should be considered the eatch value.
7 a3 O6 X' Y2 d7 {$ t  sAs a reference, the foundry resistor test key, was measured by 10u/10u or larger.