1.Film deposition
Thin film deposition is the process of creating a thin film coating on a
substrate material and depositing it. These coatings can be made from a
variety of materials, from metals to oxides to compounds. Thin film
coatings also have many different properties that are utilized to modify
or improve some factors of substrate performance. For example, some
are transparent. Some are very durable and scratch resistant. Others
increase or decrease the conductivity of electricity or the transmission of
signals.
2.Oxidation
Oxidation is the process by which a layer of silicon dioxide grows on the
surface of a silicon wafer. Oxidation of silicon is achieved by heating the
silicon wafer in an oxidizing atmosphere such as oxygen or water vapor.
Silicon has a very high bandgap energy of 1.1 eV, so it is used at high
temperatures.
3.Lithographic techniques
In modern semiconductor manufacturing, lithographers impose structure
on light rays by passing them through a "mask" and then projecting an
image onto a silicon wafer coated with a thin layer of material called a
resistor. Resists undergo chemical conversion when exposed to light.
This conversion changes the solubility of the material, so when placed in
a developer in the appropriate solvent, the potential patterned image is
converted into a patterned chemical stencil.
4.Etching
Etching is the process of making a design by making a cut in an
unprotected area of a metal surface using a strong acid or etchant.
Etching is used in microfabrication to chemically remove layers from
the surface of a wafer during manufacturing. Etching is a very important
process module and every wafer goes through many etching steps before
it is completed. In many etching steps, part of the wafer is protected
from the etchant by a "masking" material that resists etching. The
masking material is a photoresist patterned using photolithography.
5.Diffusion
Diffusion is the movement of impurity atoms in a semiconductor
material at high temperatures. The driving force of diffusion is the
concentration gradient. The various dopant species have a wide range of
diffusion coefficients, depending on how easily each dopant impurity
can move through the material. Diffusion is applied to anneal crystal
defects after ion implantation or to introduce dopant atoms into silicon
from a chemical vapor source. In the last case, the diffusion time and
temperature determine the depth of penetration of the dopant. Diffusion
is used to form the source, drain, and channel regions of a MOS
transistor. However, diffusion occurs at every high temperature process
step and can be an unwanted parasitic effect.
6.Ion implantation
Ion implantation is the primary technique for introducing dopant
impurities into crystalline silicon. This is done using an electric field that
accelerates the ionized atoms or molecules and penetrates the target
material until these particles rest due to their interaction with the silicon
atoms. Ion implantation can precisely control the distribution and dose
of dopants in silicon because the penetration depth depends on the
kinetic energy of the ions, which is proportional to the electric field. The
amount of dopant dose can be controlled by changing the ion source.
7.Metallization
Metallization is a deposition process that aims to play several roles. The
deposition of conductive material is done for the following purposes: In
addition, forming specific components within the IC, providing
important interconnect paths between the individual devices on the chip,
connecting the chip to an external package, and finally forming a
bonding pad that connects to the circuit. Allows the chip to be connected
to an external circuit. The board of the system it supports.
8.Bonding and packaging
IC, or integrated circuit packaging, literally refers to materials, including
semiconductor devices. A package is a case that encloses a circuit
material so that it can be protected from corrosion and physical damage
and the electrical contacts that connect the circuit material to the PCB
can be attached. There are many types of integrated circuits. Therefore,
regarding the outer shell, the needs differ depending on the type of
circuit, and the type of IC package to be considered also differs.