Performance of measuring contact holes using the Opti-Probe 7341 3-D RT/CD technology

Spectra of contact hole arrays with target diameters ranging from 106 to 131 nm and pattern pitch ranging from 220 to 300 nm are taken from an off-axis (65°) rotating compensator spectroscopic ellipsometry (RCSE).[1] 3-dimensional finite difference (FD3D) model developed by H. Chu,[2] is applied in the studies. To ensure accuracy of optical dispersion of each film, the simultaneous use of angle resolved beam profile reflectometry (BPR), broadband spectroscopic reflectometry (BB), and SE of an Opti-Probe 7341 are used for characterizing of the resist and BARC films. In particular, The extracted n&k dispersions are used to model the contact hole SE data using Therma-Wave's proprietary 3-dimensional RT/CD technology.[3,4] The performance of stability of both static and dynamic repeatability, uniformity, and correlation to other independent technology (i.e., SEM) will be presented in this paper.