What is silicon ingot?

Browse Encyclopedia. A. S. A salami-shaped bar of silicon, which is a single crystal, technically known as a “boule.” The ingot is the first step in chip making. High-speed saws slice the ingot into “wafers” about the thickness of a dime, which are then ground and polished mirror smooth.

Why is silicon required as a single crystal in semiconductor industry?

The first and main requirement is that the silicon used for electronic devices must be extremely pure, since very small amounts of some impurities have a strong influence on the electronic characteristics of silicon, and therefore the performance of the electronic device.

What process is used to produce silicon ingots for the manufacture of integrated circuits?

chemical vapor deposition
This is done through a process known as chemical vapor deposition, in which the wafer’s surface is heated to about 752°F (400°C), and a reaction between the gases silane and oxygen deposits a layer of silicon dioxide.

What is the manufacturing process of silicon?

The basic process for producing silicon has remained unchanged for decades: quartz or gravel (SiO2) is blended with a carbon source and superheated in a submerged arc furnace. As the mix heats, the carbon reacts with the oxygen in the quartz and forms CO gas, thereby reducing the quartz to 99\% silicon in molten form.

What is crystal ingot?

A boule is a single-crystal ingot produced by synthetic means. In the Czochralski process a seed crystal is required to create a larger crystal, or ingot. This seed crystal is dipped into the pure molten silicon and slowly extracted. The molten silicon grows on the seed crystal in a crystalline fashion.

How silicon ingot is formed?

A seed crystal silicon rod is placed on the surface of the molten silicon in the crucible, and is pulled up while rotating it, to form a monocrystalline ingot having the same orientation of atoms as the seed crystal.

Why silicon is used as a seed material for MEMS manufacturing?

Single crystal silicon is the most widely used semiconductor material as a substrate material due to its excellent machinability, mechanical stability, and the potential to combine sensing elements and electronics on the same substrate. Circular wafers made of silicon are used as substrate in most MEMS sensors.

What is a silicon seed crystal?

A boule is a single-crystal ingot produced by synthetic means. A boule of silicon is the starting material for most of the integrated circuits used today. This seed crystal is dipped into the pure molten silicon and slowly extracted. The molten silicon grows on the seed crystal in a crystalline fashion.

What is silicon wafer used for?

In electronics, a wafer (also called a slice or substrate) is a thin slice of semiconductor, such as a crystalline silicon (c-Si), used for the fabrication of integrated circuits and, in photovoltaics, to manufacture solar cells. The wafer serves as the substrate for microelectronic devices built in and upon the wafer.

What is silicon wafer fabrication?

Wafer fabrication is a procedure composed of many repeated sequential processes to produce complete electrical or photonic circuits on semiconductor wafers. The silicon wafers start out blank and pure. The circuits are built in layers in clean rooms.

Where are silicon ingots made?

Japan leads the world in silicon wafer manufacturing The cylindrical ingot is then sliced into thin circular wafers, which are polished, etched, and cleaned multiple times until their surface is as shiny as a mirror (Figure 3, bottom).

How are silicon ingots made?

How are integrated circuits made from silicon ingots?

After the silicon ingot is ground, polished, and sliced, it becomes the basic raw material for manufacturing integrated circuits-wafers. Slicing uses special internal blades to cut silicon rods into thin wafers with precise geometries. Then, the surface and edges of the wafer are polished, ground, and cleaned.

What is the growth process of a silicon ingot?

The growth process is very slow, typically 0.5 inch per hour for 150mm diameter crystals. Because of slow growth rates, the manufacturing process consumes large quantities of electricity. After the growing process is completed, the silicon ingot is evaluated for both electrical and mechanical parameters.

What are the steps involved in the production of ingots?

1 Ingot Growth. To grow an ingot, the first step is to heat the silicon to 1420°C, above the melting point of silicon. 2 Slicing. Once the ingot is fully-grown, it is ground to a rough size diameter that is slightly larger than the target diameter of the final silicon wafer. 3 Cleaning. 4 Polishing. 5 Packaging.

How to control the diameter of the ingot during crystal growing?

The diameter of the ingot during crystal growing cannot be controlled to the tolerance required by wafer handling equipment. To meet the diameter tolerance, the ingot is centerless ground to the exact diameter. Another part of the grinding process is to grind a major flat and minor flat or flats for crystal plane designation.