Wafer Coring Services

Wafer coring involves reducing the diameter of the wafer so that it fits into the available processing equipment. This saves time and money by not having to purchase new tools that were designed for the older size of wafer.

Our wafer coring services include resizing of both patterned device wafers and bare or coated (blanket film) wafers to a variety of SEMI-standard wafer diameters. These services are performed on a variety of substrates including silicon CMOS, glass and bare or coated wafers.

Resizing

In the semiconductor industry, the size of a wafer has a direct impact on how it is processed. Resizing a wafer is the process of reducing its diameter so that it fits into the available processing equipment.

Many companies have expensive, multi-million dollar process tooling designed to accommodate a specific wafer size. This poses a challenge when a wafer grows in size.

Rather than replacing costly tooling, many companies use resizing services to make the most of their existing equipment and increase the yield of post processing.

Dicing

During the wafer dicing process, individual silicon chips or die are separated from a wafer. Various methods are available to accomplish this, including scribing and breaking, mechanical sawing and laser cutting.

Typically, dicing is performed in two phases. The first step is to thin the wafer so that it fits into the available processing equipment.

The second step is to cut the wafer into smaller pieces called dice, which are then glued together. The process is automated to ensure precision and accuracy.

The dicing mechanism uses an abrasive blade that rotates with a spindle at high speeds, usually 30,000-60,000 rpm. The blades contain diamond grit embedded into an electroplated nickel matrix.

Hole Drilling

Deep hole drilling is a form of electrical discharge machining (EDM) used to drill holes that are deeper than 10 times the hole diameter. These are usually drilled to accommodate cooling, lubrication, venting or nozzle bores in aerospace, mold and die making, and medical equipment manufacturing applications.

Hole drill EDM works by sinking a rotating hollow electrode into the material to be drilled, and then pumping dielectric fluid through the electrode. When sufficient electric charge builds up to overcome the resistance of the dielectric fluid, a spark jumps from the electrode to the material to generate high localized temperatures that vaporize and erode the material.

Polishing

Polishing is the process of removing any surface irregularities and producing a flat, mirror-like surface. It can be done in two different ways, chemical mechanical polishing (CMP) and physical vapor deposition (PVD).

In chemical mechanical polishing, a mildly corrosive solution is applied to the wafer and then removed. This removes surface metals and micro particles, leaving the underlying silicon as a very polished, smooth surface.

Another polishing technique involves a surfactant that is applied to the surface of the wafer after rough polishing. The surfactant is preferably water-soluble and non-chemically reactive with silica or silicon.

The wafer surface is then allowed to dry, which is a process step that reduces the number of surface defects. However, the length of time that the surfactant is allowed to dry on the surface of the wafer is dependent upon process throughput limitations.