Optical Thickness Monitor for Continuous Vapor Deposited Film
Original Publication Date: 1986-Aug-01
Included in the Prior Art Database: 2005-Mar-09
This article discloses an optical monitor wafer which is utilized to determine the thickness of conformal metal films formed by continuous vapor deposition (CVD). Current methods of measuring CVD film thickness include the use of a scanning electron microscope (SEM) and the use of the ohms/square (Rs) method of calculating resistivity. These techniques are time consuming and complex. Moreover, where sensitive elemental compositions are altered in the deposition process, the Rs method cannot be used as a means of measurement. Fig. 1 shows a plurality of holes formed in a monitor wafer which is used to optically monitor the thickness of CVD films. Note that holes of different depths and similar widths, e.g., Y1 and Y2, fill in the same time.