# Exercise 4.1-1

## Quick Questions to

### 4.1 Input to Si Processing in an Industrial Environment

| Here are some quick questions:
|  | List (and discuss briefly) some essential inputs to a chip factory.
|  | What is the essential process for producing raw (= metallurgical) Si and what is the major use for this Si?
|  | Go through the essential of Si single crystal growth by the CZ technique. Give numbers and discuss in-situ doping, keeping the crystal dislocations-free, and any remaining problems.
|  | Describe shortly the essentials of how to obtain clean, doped poly-Si as needed for single crystal growth
|  | Where and why is a CVD process involved in making electronic grade Si?
|  | Describe the phenomenon of segregation. How does it impact Si crystal growth? |  |
|  | Given the diagram on the right, discuss: What a segregation coefficient of , e.g., 10–2 means in terms of the concentration in the crystal in the beginning and the end of the crystal growth process if the initial concentration in the melt is 10–6 Why you prefer As to Sb as a dopant during crystal growth . |
|  | Why is extreme flatness an essential condition for standard Si wafers?
|  | Why is it possible to keep wafers completely free of dislocations, but not of "microdefects" = agglomerates of point defects?

With frame

4.1.4 Summary to: 4.1 Input to Si Processing in an Industrial Environment

© H. Föll (Semiconductor Technology - Script)