Step 16. Nitride removal

 

 

Step

 

Process

Date

Operator

 

16.1

 

 

Photoresist strip

 

Matrix 5 min O2 ashing

Note: Matrix recipe was changed, temperature was lowered to 200oC, time increased to 5 min

 

07/10/07

Pongracz

 

16.2

 

 

Standard clean wafers

 

Sink8 Piranha

 

07/11/07

 

16.3

 

 

Nitride wet etch

 

Sink7

-         fresh phosphoric acid (3 bottles) @ 160 oC

-         water dripping 1 drop/10s to keep the liquid level

-         no HF dip before

 

 

Monitor the etch rate after 30 min, 60 and 90 min (QDR, SRD)

Measure oxide/nitride thickness with Nanoduv

 

Oxide thickness after etching ~ 250 A, ~100 A on opened areas

 

 

07/12/07

 

16.4

 

 

Pad oxide wet etch

 

5:1 BHF @ Sink8 until PCH dewet ~ 45 s

 

07/12/07