ECE 1406, Homework #2, Due April 15, 2003

1. 3.1, Text. The easiest way to do this is by using an oxidation chart, either from the text or from the MFL web site (which has a link on the class web site).

2. 3.2, Text. Do this problem both by using an oxidation chart, and by using the equation for oxide thickness. Calculate the rate constants using the information in table 3.1.

3. Derive the thickness ratio of SiO2 below and above the original silicon surface, as shown in Fig. 3.2, starting with the densities (Si, 2.33 g/cm3, SiO2, 2.22 g/cm3), and the molecular weights of Si and SiO2.

4. 3.11, Text. Assume that the second oxide is grown at 1000 C in wet oxygen on <100> silicon. Assume that the second oxidation grows an additional 100 nm of oxide in the already oxidized areas for a total of 300 nm, and some amount (you must determine this!) in the windows which have been cleared of oxide by the etch. In addition, more silicon will be used up in the window areas, since the second oxide grows faster there, so you should calculate the depth of this depression in the silicon, and include it in your drawing.

5. 3.18, Text.