Detailed production process of single crystal and polycrystalline silicon wafers (below) (1)
In the [Technical Application] detailed description of the production process of single crystal and polycrystalline silicon wafers, I introduced the first half of the process flow of single crystal and polycrystalline silicon wafers, and outlined some process flow and concepts, as well as related knowledge of terms. This article is from the beginning of the slicing process, to the grinding and doping, see how the silicon is transformed.
slice
Section review
When the single crystal silicon rod is sent to the silicon wafer production area, the crystal rod has passed the process of head and tail cutting, barrel grinding, and reference surface grinding, directly bonding the carbon board, and then bonding with the cutting piece can be sliced. .
In order to be able to cut a single wafer, the ingot must be cut in some way. The slicing process has some requirements: it can be cut in a specific direction of the crystal; the cut surface is as flat as possible; the damage introduced into the wafer is as small as possible; the loss of material is as small as possible.
Carbon plate
When the silicon wafer is cut from the ingot, something needs to be prevented to prevent the silicon wafer from falling loosely. Typically, carbon sheets are bonded to the ingots by epoxy bonding so that the silicon wafers are cut from the ingots and still adhere to the carbon sheets.
Carbon sheets are not the only choice for bonding sheets. Any type of bonding sheet and epoxy bonding agent must have the following characteristics: it can support the silicon wafer, prevent it from falling during the slicing process and can easily be removed from the bonding board and Epoxy peeling; also protects the wafer from contamination. Other bonding materials are ceramics and epoxy.
Figure 2.1 illustrates the bond between the carbon plate and the ingot.
Figure 2.1 Stick Figure
graphite
It is a hard material for supporting a silicon wafer, which is formed into a shape conforming to the bonding position of the ingot. In most cases, the carbon sheets should be adhered strictly along the reference surface of the ingot so that the carbon sheets can be processed into rectangular strips. Of course, the carbon plate can also be bonded to other parts of the ingot, but it should also be in the same shape as the part. The shape of the carbon plate is important because it requires the use of as little epoxy as possible and as short a distance as possible between the carbon plate and the ingot. This distance requirement is as short as possible because epoxy is a fairly soft material and carbon plates and ingots are very hard materials. When the blade is cut from a hard material to a soft material to a hard material, the wafer may be broken.
Here are some options for selecting epoxy types: strength, mobility, and degree of contamination. The epoxy bonding the carbon plate to the ingot should have a sufficiently strong viscosity to support the wafer until the entire ingot is cut. Therefore, it must be easily removed from the wafer with minimal contamination.
blade
When the silicon wafer is cut from the ingot, it is desirable that the cut surface is flat, the damage is small, the material cut in a specific direction, and the material lost is as small as possible. It is worthwhile to have a fast, safe, reliable and economical cutting method.
In semiconductor companies, two commonly used methods are ring cutting and wire cutting. Ring cutting is usually referred to as inner circle cutting and is the most widely used method of cutting an ingot into silicon wafers.
Dining Pendant Lamp ,Dining Room Pendant Light,Dining Table Pendant Light,Hanging Lights For Dining Room
Zhongshan Seekyo Lighting CO., Ltd. , https://www.seekyolighting.com