Step 29. Poly
Si etch
|
Step |
Process |
Date |
Operator |
|
29.1 |
Recipe: MXP_BARC_ETCH, 40 sec etch time (see Note) Note: Due to the micromasking effect of the non-uniform BARC surface (see Step28.), poly surface roughened out. Pay more attention on this step, maybe reduce etch time, measure BARC-poly selectivity. |
10/11/04
|
Horvath |
|
29.2 |
Poly etch in Lam5. Recipe 5003 with modified over etch step. Over etch step was modified as: press: 15mTorr PwTop: 250W PwBottom: 120W HBr: 200sccm O2: 5sccm He: 0 Main etch rate and selectivity: ~4000A/min for poly, 300-400A/min for oxide (sel.~10:1) Over etch rate and selectivity: ~2500A/min for poly, ~40A/min for oxide (sel.~60:1) Etch times: 10 sec. oxide break through (CF4) 30-34 sec main etch (manual endpoint tracing the signal - signal value was aroud 13000 on Channel A) 30 sec overetch (meaning ~50% overetch) Wafers: w#1, 3, 7, 8, 9 looks perfect w#2, 4 little residue left on the top part of the wafer w#5, 6, 10 center (2inch) area over etched |