N.Cheung, Sp 2008 EE 243: ADVANCED IC PROCESSING AND LAYOUT Homework Assignment #7 (Due April 2 Wed) Reading Assignment: PDG, Chap 5 Handouts – Sheats and Smith Chap 3 Problem 1 Dill's Model of Resist Exposure – A,B,C parameter extraction Given: ∂I(z,t)∂z= - [Am(z, t)+B] I (z, t) ∂m(z,t)∂t= - C I (z, t) m(z, t) where m is the normalized concentration of inhibitor in positive resist. Optical transmission experiment shows the following transmittance (I/Io) versus exposure time curve for a 2.2 micron positive resist. (AZ1350J). Find numerical values for the bleachable absorption parameter A , the nonbleachable absorption parameter B, and the bleaching rate C. The Iovalue is 30mJ/cm2–sec. The T12factor (air-to-resist) is 0.8.Problem 2 Resist standing waves With i-line (365nm) exposure, Shipley AZ 1470 resist has n= 1.7-j0.032 Si substrate has n = 6.52 –j2.71 a)Determine the period (min-to-min exposure) of the standing waves at i-line.b)Find the reflection coefficient from silicon seen in the resist at i-line
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