I guess it should be called micromasking instead of microloading. It was caused
by
the polymer during the CHF3 RIE etching. My suggestion is to add some O2 and
decrease the chamber pressure. A recipe that works well for us is:
RF power:300W
CHF3 flow rate:30sccm
O2 flow rate:5sccm
Pressure:1.6Pa
etch rate:27nm/min
it works well for a 3 micro deep TEOS SiO2 which is carbon-rich, the only
disadvantage of the adding of O2 is the lost of selectivity of P.R to SiO2.


ÔÚÄúµÄÀ´ÐÅÖÐÔø¾­Ìáµ½:
>From: "Hyunsoo Park" 
>Reply-To: General MEMS discussion 
>To: [email protected]
>Subject: [mems-talk] To avoid micro loading effect after RIE
>Date:Fri, 27 Oct 2006 15:26:22 -0500
>
>Hi guys
>
> I etched 1um of SIO2 with Cr mask in Oxford RIE.
> But, after RIE I see some particles(which is called microloading) on
> the SIO2 surface not the Cr surface.
> I can't remove it with Acetone and O2 cleaning.
> I have used only CHF3 gas for etching.
> I may remove it with BOE but I am concerned it would etch not only
> particles on bottome also sidewall.
> Could you please tell me how to remove it?