Si (111) and (100) Wafers and Ingots

Si (111) and (100) Wafers and Ingots - Alkali, Orientation

Material Name: Si (111) and (100) wafers and ingots
Recipe No.: 1927
Primary Chemical Element in Material: Si
Sample Type: Wafer
Uses: No data
Etchant Name: None
Etching Method: Alkali, orientation
Etchant (Electrolyte) Composition: x...5-10% KOH (NaOH). Note: The volume/quantity was not shown in the referenced article and is therefore designated as an "x".
Procedure (Condition): Time: 5-10 min, temperature: Hot.
Note: Si (111) and (100) wafers and ingots. ingot growth direction can be established by observing the direction of the hachure miniscus locations on ingot sides...3 on (111); 4 on (100) ingots. The hachure marks point upward toward the seed ingot end. This can be used to establish a (111)A or (TTT)B wafer surface direction. By cleaving a portion of a (111) wafer edge and etching in KOH or NaOH will develop triangle etch pits on the cleaved edge. If triangle points are downward, bulk plane is (011); if upward toward (100) posilivi; wafer surface, with 180° rotation, it is (01T) which is the preferred orientation for channel and pit etching.
Reference: Perrin Walker, William H Tarn: Handbook of Metal Etchants, CRC Press, Boca Raton, Florida, USA, 1990, p. 1068-1069.