Wafer Chucks

ARC, in addition to fabricating Wafer Chucks from aluminum, is also known for its ability to work in hard to machine materials such as hardened (50-62 Rockwell) metal alloys, fired ceramics, e.g. SiC and glasses. These materials are often ideal for semiconductor equipment applications due to their ability to hold critical dimensions and tolerances. ARC specializes in surface grinding and lapping these materials to precision flatness and parallelism specifications needed for semiconductor wafer chuck requirements.

A new wafer chuck material is Materion’s SupremEx (AlSiC). This material is a very strong and lightweight alloy of Aluminum and Silicon Carbide. ARC is currently processing parts using this novel material. For more information on SupremEX visit: http://www.materion.com

Porous Ceramic is another interesting class of materials. These materials are ideal for vacuum wafer chuck applications. They are available in various pore sizes which can be tailored to meet a customer’s vacuum requirements. Following machining, porous chuck are cleaned in a class 200 clean room prior to a quality review and shipment.

Wafer bonding chucks

Shown on the right are various 8” (200mm) Stainless Steel and Silicon Carbide chucks. These devices are machined from high quality stainless steel and silicon carbide flat stock.

The material is precision ground to within a few microns over the 8” diameter. Each wafer chuck is inspected using Tropel surface analysis.

Figure 1 SS Wafer Bonding Chuck - Base Plate
Figure 1 SS Wafer Bonding Chuck - Base Plate
Figure 2 SiC Wafer Bonding Chuck - Base Plate
Figure 2 SiC Wafer Bonding Chuck - Base Plate
Figure 3 SiC Wafer Bonding Chuck Set
Figure 3 SiC Wafer Bonding Chuck Set

Zerodur Glass Wafer Chucks

Machining glass can be a difficult challenge which requires an effective CNC tool path in order to produce high quality features. ARC has perfected the ability to machine Zerodur and other glasses and plastics.

Zerodur has two outstanding qualities that make it a perfect choice for certain applications where transparency and extremely low coefficient of thermal expansion are needed. For example, Zerodur is the desirable choice when there is need to see through the chuck to observe features on the wafer itself such as fiducials needed for alignment purposes.

Figure 4 Cam view of the Zerodur Chuck
Figure 4 Cam view of the Zerodur Chuck
Figure 5 Zerodur Glass Chuck
Figure 5 Zerodur Glass Chuck

Porous Ceramic Chucks

Porous ceramic wafer chucks are an ARC specialty.
The Plate shown in Fig. 6 is a 6” porous ceramic plate in a stainless steel base being tested for flatness using a submicron drop gauge.

The plate shown in Figure 7 is a Ni plated Aluminum base with vacuum access holes and a porous ceramic wafer surface which has been ground flat to within 8um in flatness and parallelism across the 12 inch surface.

Porous Ceramic Vacuum Chuck with micron flatness
Figure 6 Porous Ceramic Vacuum Chuck with micron flatness
Figure 7 12 inch Porous Ceramic Chuck with a 16 inch Ni Plated Aluminum Base
Figure 7 12 inch Porous Ceramic Chuck with a 16 inch Ni Plated Aluminum Base

Custom Wafer Chucks

Various chuck types used for wafer processing e.g.  Dicing, include Electrostatic, Magnetic, Vacuum, and Thermal chucks.

ARC will design a wafer chuck to a customer’s unique requirements and quote the finished product.

ARC also manufactures custom chucks from a customer’s drawing or solid model. Shown on the right is a 6 inch diameter free standing porous ceramic chuck plate with pores size 20um +/-10%.  15 – 55 um are typical options, other pore sizes may also be available. Edge vacuum sealing is also an options.

Figure 8 Porous Ceramic Vacuum Chick
Figure 8 Porous Ceramic Vacuum Chick

Replacement and Refurbished Wafer Chucks

ARC makes replacement chucks as well as refurbishes OEM dicing chucks such as those used in Disco and K&S wafer dicing machines. The old ceramic is measured if a drawing is unavailable. The ceramic is then removed and the chuck base is inspected, cleaned and prepared for attaching the newly machined ceramic disc. Shown on the right is a solid ceramic plate with vacuum traces machined into the plate along with the vacuum supply hole.

Once the new disc epoxy has cured, the chuck assembly is ground flat and parallel to within the original manufacturer’s specification or better.

Figure 9 Before Repair (Left) After Repair (Right)
Figure 9 Before Repair (Left) After Repair (Right)