Exercise 4.4-1

All Quick Questions to

4. Getting Started

Subchapter 4.1: Input to Si Processing in an Industrial Environment

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?

	Subchapter 4.2: Other Semiconductor Growth Technologies
		Describe some problems encountered (and the solutions) when growing III-V single crystals.
		What are the incentives for trying to get SiC "to work"? Describe the specific problems encountered when growing SiC single crystals.
		Provide and describe major products not based on single crystal semiconductors.
		Explain the follwong abbreviations and give possible uses: a-Si:H, µc-Si:H, CIGS.

	Subchapter 4.3: Infrastructure
		"Cleanroom class 100" means roughly....?
		Describe the effects of particles on, and contamination in the chip.
		The electrically crucial area of an integrated transisitor is (50 × 300 ×300) nm³. The lattice constant of Si is roughly 0.5 nm; there are .... atoms per elementry cell. An Au concetration of 1 ppb "kills" the transistor. How many Au atoms can you tolerate in your transistor? If you touch a gold ring and 1 out of 1 billion surface atoms gets stuck on your finger - how many roughly are now on your skin?

With frame

4.4.1 Summary to: 4. Getting Started