What Is Wafer Polishing? | Silicon Specialists LLC

Wafer polishing is a process that is used to create the optimum condition for the semiconductor, whether it is silicon or another material. This is done by a chemical or mechanical process that aims to remove the stresses and warping. The main advantage of this process is that it masks the defect and improves the appearance of the chip.

Chemical-mechanical polishing

Chemical-mechanical polishing (CMP) is a planarization technique that is widely used to remove material from semiconductor wafers. The process involves applying a slurry of chemicals to the wafer surface and abrasive particles to remove the material.

This technique is effective for removing layers of material from silicon wafers. It is particularly effective at planarizing layers of a wafer. However, the aggressive nature of the mechanical polishing techniques tends to reduce the uniformity of the polished surface on the wafer.

In order to enhance the removal rate of a semiconductor layer, a chemical-mechanical polishing slurry is applied. Slurries typically contain oxidizer. They can also contain stray particles from the wafer, but these are removed during post-polishing clean-up.

A chelating agent is also deposited on the polishing pad. Chelating agents are believed to chelate with the surface moieties, making them easier to dislodge. Preferably, the chelating agent is selected to react with polish-resistant surface moieties on the wafer.

The present invention is a method for chemical-mechanical polishing of a semiconductor wafer surface, comprising steps of positioning a wafer adjacent to a polishing pad. Steps of moving a wafer and a polishing pad are also described. Typically, the size of the polishing pad is around 50 to 75 cm.

Masking effect

Photolithography is a key process in the manufacturing of digital devices. A photomask is a thin layer of masking material that is patterned to absorb light at varying intensities and to support a thicker substrate.

In its simplest form, a photomask can be thought of as a stencil that serves as a template for a semiconductor manufacturing process. Its physical structure is also referred to as the frame. The frame is usually built by a fab after the primary pattern size has been determined.

In addition to the basic lithography steps, a photomask has other design elements. An important element is the die, which is a solid structure that is designed to receive the primary pattern. This is typically arrayed on a reticle inside the frame.

Another element is the dummy fill, which serves no electrical purpose. However, it can make the wafer more planar for CMP polishing. Dummy fills are often made of uniformly spaced square-patterns.

Finally, a photomask can be patterned with a custom design. These can include mirroring, rotation, or fracturing. Fracturing may involve the application of a boolean operation. There are a variety of sizing techniques, which can be applied during the mask process or during the etching of the wafer. The amount of sizing is dependent on the type of photoresist and etching process.

Removal of stresses and warping

Silicon wafer polishing is a process that involves removing some of the stresses and warping that can occur during semiconductor production. In order to do this, a variety of steps must be performed. Some of these steps include physical polishing and chemical and mechanical polishing.

For this purpose, a thin film with a small amplitude of dopant striations is used to generate the small amount of stress that is required to create a smooth surface. This is done by applying a polishing solution containing an alkaline etchant.

Aside from this, there are numerous other steps involved in the process. Each step is important in achieving a smooth surface. There are two primary methods of polishing silicon wafers. The first is known as kerf-less polishing. It entails pouring molten silicon into a mold that is shaped like a spherical wave.

The second method, referred to as double-sided polishing, involves using a combination of physical and chemical polishing techniques. While this method produces a smoother, more uniform surface, it requires more equipment and technicians.

Although the double-sided polishing process is more expensive, it produces a surface that is better suited to thin-film applications. The main reason for this is because it reduces the amount of micro-scale damage.