Semiconductor Basics (outline of the course and some basic terminologies)

Here, I will give the detailed information about semiconductor from very basic to a advanced level.

I will try to provide some interview questions that has been asked in different semiconductor companies.









ok, so here we go,

So, What you  need to know if you want to go into a semiconductor industries (here, my focus is on VLSI)

You should have  clear concepts of some subjects as I have disscussed below. (You can skip the advanced part if  you are a fresher).

1. Analog electronics

:  Capacitor, Diode,  BJT, FET , MOSFET, Oscillator, Op-amp, 555 Timer

2. Digital electronics

:logic minimization, k-map,Sop,Pos,AOI, Adder, Subtractor, combinational, and sequential circuits, state machine, counters, registers and its types, conversion of flip-flops  etc....

3. Physics of semiconductor

: Good understanding of semiconductor and its types

:Good understanding of mos capacitor with band diagram

4.  Basic VLSI

mosfet, cmos, voltage and transfer characteristics of cmos, Different regions of operation of cmos, stick diagram etc.

5. Advance VLSI

a. static time analysis

: Setup time and hold time

: time exceptions

:false path, multi-cycle path etc.

b. About different  physical cells

c. latch-up issue and its solution

d. Antenna effect and its  solution

e. PnR flow

f. Different updated technologies used by the semiconductor companies.

So, here we go one by one:

Before starting semiconductor we should have some basic knowledge about signal , voltage, current etc.

signal contain information about a variety of things and activities in our physical world.like Information about the weather is contained in signals that contains the air temp. , pressure, wind speed etc. 

Now the question is  how to extract the information from that particular signal?

> extract the information from the signal one needs to process the signal(means signal will go through some process) in some  predetermined manner.

For this to be possible signal must be converted into electrical signal, e.g voltage and current

This process accomplished by a device known  as Transducer.

>> Don't confused with the term signal processing its just like, if you need oil from coconut then to extract the oil, coconut must go through some process . 

Types of signal

1. Analog

2. Digital

1. Analog signal: It derived from the fact that such signal is analogous to the physical signal that it represent.

It can take any value at any time within the given limit.

e.g, The amplitude of an analog signal exhibits a continuous variation over its range of activity.

* An analog signal may be continuous or discrete in nature

--> All continuous signal is analog in nature but not all analog signal is continuous in nature.

>> If time is discretized (i.e the independent variable is discretized) but not  the amplitude (i.e dependent variable is not discretize) it's still an analog signal.

To get the clear view just see the fig1.1b and fig1.1c given below.

>>Now you may have doubt that how amplitude is dependent and time is independent?

 See the fig carefully, the amplitude is changing w.r.t time so, it's depends on time.

at time t1 temprature is 1c at t2 temprature is 2c and so on. so, here the temp. is increasing with increase of time. hence, we can say that amplitude (here Temp.) depends on time. while we can clearly obseve that time is independent variable.

>> Guys do not get confuse with the term discretize, it's just a specific value of signal at a specific time instant. It can be obtained by sampling a continuous signal. in fig1.1a and fig1.1b and  the samples are taken at various time instant these instant may be regular or irregular.

fig1.1a

fig1.1b

When I will discuss about digital signal in detail then you will get more clear idea.

2. Digital signal: It's a representation of signal as sequence of numbers, each numbers represents the signal magnitude at an instant of time, the resulting signal is called as Digital signal