Specific Process Knowledge/Etch/KOH Etch: Difference between revisions
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==KOH etch - ''Anisotropic silicon etch''== | ==KOH etch - ''Anisotropic silicon etch''== | ||
[[Image:KOH_4tommer.jpg|300x399px|thumb|KOH etch for 4" wafers: positioned in cleanroom 3]] | [[Image:KOH_4tommer.jpg|300x399px|thumb|KOH etch for 4" wafers: positioned in cleanroom 3]] | ||
KOH belongs to the family of anisotropic Si-etchants based on aqueous alkaline solutions. The anisotropy stems from the different etch rates in different crystal directions. | KOH belongs to the family of anisotropic Si-etchants based on aqueous alkaline solutions. The anisotropy stems from the different etch rates in different crystal directions. The {111}-planes are almost inert whereas the etch rates of e.g. {100}- and {110}-planes are several orders of magnitude faster. | ||
At Danchip we use as a standard a 28 wt% KOH. | |||
Revision as of 10:31, 28 January 2008
KOH etch - Anisotropic silicon etch
KOH belongs to the family of anisotropic Si-etchants based on aqueous alkaline solutions. The anisotropy stems from the different etch rates in different crystal directions. The {111}-planes are almost inert whereas the etch rates of e.g. {100}- and {110}-planes are several orders of magnitude faster.
At Danchip we use as a standard a 28 wt% KOH.