Method for Measuring Membrane Thickness
Original Publication Date: 1985-Apr-01
Included in the Prior Art Database: 2005-Feb-18
An electrostatic chuck may be used to hold a thin film membrane flat so that a profilometer can be used to measure the film thickness. The profilometer technique measures film thickness by moving a stylus across the film to be measured. When a variation occurs in the film thickness, the stylus is either pushed up or drops down depending on the direction of the change in thickness. The vertical position of the stylus is detected electronically and plotted against the horizontal motion of the stylus, thereby indicating the change in the film thickness. This technique has not been used to measure free-standing or absolute film thicknesses in the 0.1 to 250 micron range, since there has been no satisfactory method to keep the thin film in place and to prevent it from curling. The method described here solves these problems.