Characterization of the anisotropic chemical attack of {hk0} silicon plates in a TMAH solution - Determination of a database

This paper is devoted to the study of the anisotropy of the chemical attack of (h (k) over bar 0) silicon plates in a water-T.M.A.H, solution 25% in w eight. In the first part 12 different orientations were investigated and em phasis is placed on the changes in the geometrical features of etched (h (k ) over bar 0) surfaces and in the starting circular section of thick (h (k) over bar 0) plates with the angle of cut. In the second part orientation e ffects in 2D experimental etching shapes are analysed to determine a databa se (composed of dissolution constants) which characterizes the anisotropy d f the T.M.A.H. etchant. The adequation of the database is then discussed by comparing the experimental 2D etching shapes with theoretical shapes as de rived from the database using a kinematic and tensorial model of the anisot ropic dissolution. (C) 1999 Elsevier Science S.A. All rights reserved.