Ion Implantation Method For Si Wafer Fabrication

Ion implantation is a material engineering process. In this method ions are accelerated in an electrical field and impacted into a solid. This process is used to change electrical and physical properties for semiconductor device fabrication. 

This method was developed for producing the p-n junction of photovoltaic devices. It can also be used for making pulsed-electron beam for rapid annealing. Ion implantation is a very popular process because it provides more precise control of dopant in comparison to diffusion. Ion-implanted species relies on a rapid thermal annealing technique.

The ions alter the elemental composition of the target. Many chemical and physical changes are done to change the structural properties of the crystal. Since the masses of the ions are similar to target atoms, they knock the target atoms from their place.

This method allows movement of impurity atoms within the crystal structure. Thus, diffusion process has become less important than methods for introducing impurities into Silicon Wafer Pricing.

Benefits of Ion Implantation Method of Silicon Wafer Fabrication:

•             Provides precise control over the density of dopant deposited onto the wafer.
•             Improvement in the quality of ICs.
•             Helps in achieving very large values of sheet resistance.
•             High sheet resistance value is helpful in gaining large resistor value.
•             Assist in low temperature Ion-implantation.
•             Enables Reduced tendency for lateral spreading of wafers.
•             Helpful in adjustment of the threshold voltage of MOSFET’s.

This method is utilized by some of the prominent Silicon Wafer Supplier, for preparing silicon wafers from conventional silicon substrates. Within the past few years, it has become a very powerful tool for Semiconductor Fabrication. Its attributes of controllability and reproducibility makes it a very versatile tool.

Classification of Semiconductor: Intrinsic and Extrinsic

The silicon is the heart of any electronic Industry. Semiconductors have a vast impact on our society. These lies at the heart of microprocessor, chips and transistor industry. The semiconductors are the compound which has a good electrical conductance, generally intermediary between the insulator and a conductor. These are the basic component of various kinds of electronic circuit and device used in communications, Information technology and in computers.

Classification of Semiconductor:

Semiconductors come in a variety of designs and types. They can be classified as per their dopant types. This article explains all these differences in detail, Two basic kinds of semiconductors are:

Intrinsic Semiconductors

The pure form of semiconductor is called as intrinsic semiconductor. It can also be stated as semiconductor is which conduction band have equal number of holes and electron ration.

These have very minute forbidden energy gap. The energy available at room temperature is enough for the valence electrons to jump across the conduction band. Another characteristic feature is that the Fermi level. Their Fermi Level lies in between the valence band and the conduction band. 4"Silicon Wafers is best known example of intrinsic semiconductors.

Extrinsic Semiconductors

In these semiconductors the pure state is deliberately diluted by adding impurities into it. Such  impurities when added to 100mm Silicon Wafers, are known as doping agents or dopant. The materials chosen for doping either have 5 electrons or 3 electrons in their valence shell. Such,  dopants are either known as pentavalent or trivalent dopant.

Method of Testing Silicon Wafers

Wafer testing is an important step of semiconductor device fabrication. The wafer testing is done by test equipment known as Wafer Prober.

Types of Wafer Testing:

             1.      Wafer Final Test (WFT)

             2.      Electronic Die Sort (EDS)

             3.      Circuit Probe (CP)

During this process, Silicon wafer is sent for die preparation. In this process, Integrated circuits present on the wafer are tested for functional defects. This is done by applying the special test pattern.

The Wafer Prober’s Role is Silicon Wafer Testing:

Wafer probe is a device used to test integrated circuits. A probe card is used for electrical testing of the silicon wafers. The Wafer is moved into electrical contact by means of Vacuum-mounted on their surface. Die electrically test the Prober to start the next test. The wafer Prober is equipped with automatic pattern recognition optics. It is responsible for loading and unloading of the Silicon wafers. It is also capable of aligning the wafers together. The Silicon Test Wafers probe exercises test circuitry on the wafer scribe lines.

Non-Contact Wafer Testing

This method is for Silicon Test Wafer. It is an alternative to mechanical probing of integrated circuits. In this method, tiny RF antennae are used to replace both the mechanical probes and the metal probe pads.

Benefits of Non-Contact Wafer Testing:

             1.      No damage is done to circuits and probe cards.

             2.      No debris is produced

             3.      Probe cards are not required.

             4.      Wireless probe points can be placed anywhere IC

             5.      The wafer probe does not exert any force on the Silicon Wafers.

             6.      Repeated probing is possible without damaging the probe points

             7.      Faster data rates are possible than with mechanical probes

Introduction to Wafer Bonding System

Silicon wafer bonding is a procedure that permanently or temporarily joins two substrates or wafers. This method helps in preventing slipping, breakage, warping and die fly-off during wafer polishing, dicing, grinding, lapping operations and head mounting.

Wafer bonding is basically used:

• To manufacture SOI (Silicon on Insulator) wafers. 
• To generate intricate 3D cavities and structures, this crafts device functionality. 
• In packaging methods to make close environments (vacuum packages for optical, resonators and IR procedures). 
• In integration technology for combining two chips fabricated discretely (MEMS+CMOS). 

Silicon Wafer Bonding System:

Easy to handle wafer grip thin film adhesive is positioned between the wafer and mounting base or substrate. It can be secured by using either the high quality bonder or a hot plate for enhanced processing repeatability and cycle time. By means of a uniform thickness,  wafer bonding agent bonds the 4” silicon wafers for preserving the highest adhesion for after bonding procedure. A heated solution minimally dissolves the wafer glue, raising the high quality die yield without disturbing the production routines.

Silicon Wafer Bonder:

Use of the wafer bonder for mounting substrate to wafer enhances repeatability and bond quality for improving the process time during polishing, dicing or lapping.

Thin Film wafer Adhesive:

The thin film advanced composite film resin is engineered to bond wafers optics, thin film heads and other wafer substrates during grinding, dicing, polishing and lapping. 

Understanding the Silicon Wafer

Are you looking to buy silicon wafers? Here are some important points that you need to consider while buying a wafer product. You must consider the quality of material being used to fabricate, diameter of the wafer and resistivity.  

Type of Silicon Wafers:

The wafer type depends on the conductivity requirements. Wafers carry a particular charge and commonly referred to as either N-Type and P-Type.

• N-type Silicon Wafers: Silicon wafers that have more electrons in their current carriers are negative charges and referred to as N-Type.
• P-type Silicon Wafers: When Silicon wafers are missing electrons from their current carriers, they have a positive charge, so they are P-Type.

Charges on the silicon wafers is given by the addition of dopants. P-type silicon wafers are produced by doping with boron. It produces positively charged silicon wafers. Doping with  Phosphorous, Antimony, and Arsenic produces N-Type wafer  carry  a negative charge on the surface.

Dopant and its effect on Resistivity:

The Dopant is an impurity that is added to the silicon during the production process. A dopant  functions by altering the chemical properties of the silicon wafer. Therefore, resistivity of a silicon wafer greatly depends upon the Dopant and the amount in which it is doped.

Property of Resistivity:  

Resistivity refers to the current flow and electron movement in the silicon. Depending on the purpose of the wafer, the resistivity needs to be altered through doping. The resistivity is decreased by adding more dopants to the silicon. Materials that have been heavily doped used to have lower resistivity.

Understanding Wafer Size:

Silicon Wafer Pricing is an essential element in the realization of integrated circuits production and manufacturing. Increasing the wafer size requires a lot of investment. Silicon wafer manufacturing technologies were re-engineered to achieve the necessary increase in the wafer size. In the last few years, wafer size has increased from 1 inch wafers to300mm i.e. 11.8 times larger. Many manufactures are working on a clear plan to increase the wafer size to1.5 times larger than 300mm. A larger wafer diameter enables producing more semiconductor devices from a single waferto enhance the productivity and efficiency. 

Important Points to Consider Before Buying Silicon Wafers

The Wafer is a thin semiconductor material made up of silicon crystal used in fabrications of the integrated circuits. Similarly, you will be able to find solar wafers that are mostly used for the solar panels that are installed on top of the roofs. Solar wafers have the ability to attract the light and heat from sunlight and produce electricity. This is the main reason, why a lot of people are installing the wafers in their offices and homes.

Using solar wafers you can produce your own electricity. Most of the people find it difficult to buy a good quality silicon wafer from their area. If you are one of them, researching on the Internet could be the best option. You can go through various websites from which you can choose the finest silicon wafer.

However, before buying wafers for your solar panels online, it is very important to perform a careful research. Also ensure that you are obtaining the right quality product. There are many websites that are providing wafers online, but not all of them can provide you a good quality product. Only buy from well established and reputable silicon wafer suppliers.

Therefore, before buying the wafers, it is very essential to perform a small background research of the silicon wafer supplier and make sure you are receiving high quality for the money you invest. You can also compare and choose the best wafer as there are many products of different companies available online. This is also one of the amazing benefits of buying wafers online.

Furthermore, you can compare the prices and choose the best according to your budget. In case, if you are not able to get the right wafer according to your requirement, taking the assistance of an expert could be the best option. As they will consider your needs, budget and help you in choosing the right silicon wafer.

Learn About the Quality & Cost of Silicon Wafers

Silicon is non-metallic and gray. It is available in large scale in nature. It has unique characteristics that have helped transform the world we live in today. One of the main characteristic is its ability to conduct electricity and because of this, it has become the essential material for the semiconductor industry.

Whatever revolutions we are seeing from over the last decade in the communication and digital equipment is because of Silicon and its unique characteristics. If you are in a business that buys wafers for the semiconductor market, there are number of considerations that should be at the forefront of your mind. The inherent quality and the cost of the product are indeed crucial factors.

It is very important to familiarize yourself with the factors that affect  the cost to ensure that your business sells these products at a higher price to increase profit. Price of silicon fluctuates depending upon the external forces like the global economy, political decisions and availability of the raw materials.

There are number of different mechanical specifications of the wafers for example, thickness, diameter and variation of thickness. For a wafer to function properly, there should be a uniform specification  with no room for error or deviation. Some other important factors are the edge, flatness, and bow, all of these should be uniform. The wafer needs to be completely smooth, also devoid from any abrasion caused during the manufacturing process and thin film deposition.

Every silicon wafer has to be particle-free. If there remains even a single particle on a polished surface of a wafer, this will impact its functionality. Due to this reason, calibration usually includes a traceable particle standard to determine the cost and quality. Some clients want a layer of silicon dioxide on their wafers in order to create an electrical insulation layer on the bare silicon. These types of silicon wafers are known as thermal oxide silicon wafers. They are referred to as thermal oxide silicon because the silicon oxide layer is thermally grown at a very high temperature to a desired thickness on both sides of the wafer.

The manufacturing process of silicon wafers is very tedious and complicated. It is a process which involves number of small sequential processes that are required to create an electronic circuit.