Semiconductor Wafers and the Importance of Polishing

In the world of semiconductors and electronics, very thin slices of crystalline silicon are known as wafers. These wafers are used to create integrated circuits and solar cells. For the best results, a semiconductor wafer must have a smooth and very shiny finish. When the wafers are first created, they are ground down to a fine, thin surface. This leaves subsurface damage on the wafer that must be removed.

The Polishing Process

This is where silicon wafer polishing comes in. Special pads and a substance made of liquid diamonds or weak acids are used to deliver the superior shine required in semiconductors. Essentially, the unwanted texture left during the grinding and sawing process is buffed away. A special vacuum carrier holds the wafer in place, and the wafer is gently moved toward the pad until they make contact. With precise movements, the subsurface damage on the wafer is removed a bit at a time. In the end, a highly functional silicon wafer is created. This process is completed as quickly as possible to avoid possible contamination or damage.

Diamond Cubic Structures

It may be noted that as the crystal structures of the wafers develop, diamond cubic structures are created. Thus, when the structure is cut into wafers, there’s a potential for several different crystal orientations. The differing orientations have unique electronic and structural properties. The manner of cutting, cleaning, scoring, and notching can affect the efficiency of the wafer.

The Demand for Thinner Wafers

Today, there’s a growing demand for ever thinner, ever smaller wafers, and sometimes conventional manufacturing methods leave damage on the surface of those wafers. Effective polishing can remove that damage. Micro-defects and scratches don’t have to cause trouble or weaken the wafer. Instead, high-quality polishing gets rid of the uneven texture on the wafer’s surface.

Wafer polishing is essential to the efficient use of silicon wafers. Consider the benefits of a double-sided polish for meeting required SEMI standards and specifications.