FREE ENGINEERING AND STUDY GAMES ABOUT SOLID

PDF Download

FREE ENGINEERING AND STUDY GAMES ABOUT SOLID

STATE DEVICES EXAM QUESTIONS

Qs and Ans Expert- Explanation

This Exam contains:

-Guarantee passing score -22 Questions and Answers -format set of multiple-choice -Expert- Explanation

Question 1: Can you just buy raw semiconductors (not in a circuit)?

Answer:

Yes.

Question 2: The following are semiconductors...

Answer:

Silicon(Si),Germanium(Ge),Diamond,Gallium Nitride(GaN)

Question 3: A unit cell is

Answer:

the smallest part of a crystal that has no periodicity in itself.

Question 4: Doping means...

Answer:

to put certain atoms in a semiconductor or the insertion of controlled impurities.

Question 5: Where do most of today's semiconductors come from?

Answer:

they are made by industries.

Question 6: Why do impurities matter?

Answer:

Impurities affect the transport properties of a semiconductor. It can make semiconductors highly conducting (shallow donors or acceptors) or highly insulating (deep traps).

Question 7: What were the motivations for people to develop semiconductors?

Answer:

To have materials whose electrical conductivity can be controlled.Question 8: True or False: Impurities will always make a semiconductor useless.

Answer:

False.Question 9: Epitaxial growth means:

Answer:

the growth of a semiconductor on the surface of a semiconductor.

Question 10: Where can you find GaAs?

Answer:

Cell phone, TV remote, TV satellite dish

Question 11: What is a semiconductor?

Answer:

a material whose electrical conductivity can be controlled over a wide range from near-insulating to metal-like conducting.Question 12: What property makes semiconductors special for electronic device applications?

Answer:

engineerable conductivity

Question 13: Before the development of semiconductor devices, people:

Answer:

did computation with mechanical devices(e.g. abacus, mechanical gears, etc.) and metal and glass-bulb electrical devices.

Question 14: The lattice constant is

Answer:

one of the dimensions of a unit cell.Question 15: An unintentionally doped semiconductor is:

Answer:

a semiconductor that gets doped accidentally during the growth.Question 16: Why is crystalline semiconductor more desirable than polycrystalline and amorphous?

Answer:

because electron speed is much faster in crystalline.Question 17: A doped semiconductor:

Answer:

has a different electrical conductivity than before doped.

Question 18: The development of semiconductor devices improved what?

Answer:

Radio, telephone, wireless communication.

Question 19: Energy bandgap is?

Answer:

the span of energies that lie between the valence and conduction bands for insulators and semiconductors.Question 20: How many crystals do people want to get, when they grow a big boule?

Answer:

just a single crystal.

Question 21: Why do people try so hard to grow semiconductors rather than take it from nature?

Answer:

because they want a very pure crystal.Question 22: True or False: A zero-impurity polycrystalline semiconductor is always more valuable than a single-crystal semiconductor with impurities.

Answer:

False. Controllable impurities are desirable because this is how we make devices.