Hi all.,

generally in my case after etching in Bufferd HF.,it
creates a surface roughness which is usually few
Angstroms (100 - 120 A) for etching 1500 A film.

So, i dont think etching by bufffered HF creates rough
surface thereby the light exposure may get scattered.

You can try with agitation to get more of a smooth
surface.I tried this before and got a smoother surface
(u can read the smoothness by surface profilometer)

Pls. Others share their views to confirm this.

Bala.



--- Zuraini Dahari  wrote:

> Hi all,
>
>     I am using silicon nitride as the masking
> material.
>   I've checked the previous emails that 400-500A
> should be sufficient in my case.
>   However I've got 2000A of silicon nitride on a
> silicon wafer.
>
>   I am aware that HF and H3PO4 could etch the
> nitride layer.
>   I'm planning to etch out 1500 A of the nitride
> layer before any lithography and etc.
>   My concern is, will the etching has any negative
> impact to other process later on?
>   Really appreciate for any help.
>
>   -newcomer-