System and method for step coverage measurement

摘要

Determining an unknown step coverage of a thin film deposited on a 3D wafer includes exposing a planar wafer comprising a first film deposited thereon to X-ray radiation to create first fluorescent radiation; detecting the first fluorescent radiation; measuring a number of XRF counts on the planar wafer; creating an XRF model of the planar wafer; providing a portion of the 3D wafer comprising troughs and a second film deposited thereon; determining a multiplier factor between the portion of the 3D wafer and the planar wafer; exposing the portion of the 3D wafer to X-ray radiation to create second fluorescent radiation; detecting the second fluorescent radiation; measuring a number of XRF counts on the portion of the 3D wafer; calculating a step coverage of the portion of the 3D wafer; and determining a uniformity of the 3D wafer based on the step coverage of the portion of the 3D wafer.

主权项

1. A method of characterizing a film on a 3D device, comprising:
exposing the film to radiation of sufficient energy to excite secondary X-ray emission from the film; detecting the emission from the film; quantifying the emission as a count1; retrieving a count0; determining a multiplier factor N; and calculating a step coverage; wherein the count0 is derived from a measurement of secondary X-ray emission from a planar device; wherein the multiplier factor N is derived from an actual surface area of the film on the 3D device; wherein the step coverage comprises a ratio resulting from the division of the count1 by the count0; and wherein the calculating of the step coverage further comprises multiplying the ratio by the multiplier factor N.