Specific Process Knowledge/Etch/Etching of Silicon/Si etch using ASE: Difference between revisions

The shallolr recipe is designed to etch features (with sizes above 1 <math>\mu</math>m) in silicon down to a depth that ranges from a few microns to some 50 microns. (If you need to etch deeper use Deepetch or more shallow, see Nanoetches.) It is specified to etch a 2 <math>\mu</math>m wide trench down to a depth of 20 <math>\mu</math>m on a wafer that has a global/local etch opening density of 10%.

Image:jmlshal070921 pos1 2mu_09.jpg|The profile of a 2 <math>\mu</math>m trench

image:jmlshal070921 pos1 50mu_08.jpg|The profile of a 50 <math>\mu</math>m trench

The process is designed to reach 20 <math>\mu</math>m down in a 2 <math>\mu</math>m trench but as is clear from the image of the corresponding 50 <math>\mu</math>m trench, this one is etched deeper. The reason is the so called Aspect Ratio Dependent Etching or ARDE: See below.