Knowledge Base Fact Sheet

Semiconductor wafer selection is key to a successful use of wafers and substrates for your process. Wafers are manufactured with very high precision, with attributes specific to the electronic and mechanical properties and any coatings applied after manufacture.

Wafers are manufactured from four main materials:

• Silicon
• Glass and Fused Quartz
• 3-5 or 2-6 Compound Semiconductors
• Sapphire

The figure below describes Inseto’s nomenclature chart for Silicon wafers:

The second category of wafers we classify is coated wafers. These are wafers with an added layer either on both the top and bottom surfaces of the silicon or just one of the surfaces – usually the top.

The figure below shows Inseto’s nomenclature chart for Coated Wafers:

The third category of wafers we classify is glass wafers. These are used when a transparent substrate is required and are categorised by a different set of parameters.

The figure below shows Inseto’s nomenclature chart for Glass Wafers:

The fourth category we use to classify our wafers is SOI wafers or Silicon-on-Insulator.

These wafers are a sandwich of silicon-insulator-silicon. The insulator is typically silicon oxide or sapphire and the make-up of these is highly specific to the end application.

The figure below shows Inseto’s nomenclature chart for SOI Wafers:

The fifth category we use to classify our wafers is as SOS – Silicon-on-Sapphire.

These wafers have an EPI Silicon layer on Kr grown Sapphire Wafers. The figure below shows Inseto’s nomenclature chart for SOS Wafers:

The final category we use to classify our wafers is Sapphire.

These wafers are prime grade high quality with C, A and R plane crystal orientation from 2″ to 150mm. They are Single or double side polished have low roughness and are defect free.

The figure below shows Inseto’s nomenclature chart for Sapphire Wafers: