Electrostatic chucks

Close contact of the wafer to the surface of the heater block is another important factor that determines uniformity and reproducibility of the deposition. In addition, the heating time of the wafer to the desired temperature after chamber loading, which takes normally a few minutes and reduces throughput, also depends on the contact status. The electrostatic chuck (ESC) may... 

Sun HCS. Method of making pharmaceutical using electrostatic chuck. US Patent 5,846,595, 1998. 

Sun HCS. Electrostatic chuck and particle deposition apparatus there for. US Patent 5,858,09, 1999. 

A processing chamber in which only one wafer is implanted at a time is typically employed for medium current implanters. The endstation consists of a single scanning arm capable of linear motion of up to 140-200 mm s 1. over a range of up to 400 mm. The wafer is typically held on an electrostatic chuck which may be gas-cooled to maintain adequate wafer temperature. 

Another challenge faced by SCALPEL technology is related to the fact that the SCALPEL mask is not protected by pellicles, making particulate and airborne molecular contamination a major issue. In particular, many components of the SCALPEL tool are sensitive to the presence of charged particulates these include electrostatic chucks, electrostatic optics, and apertures. The fact that the SCALPEL tool is designed to operate in a vacuum environment (10 torr) has been reasonably effective in limiting the amount of particulate and molecular contamination, but has not eliminated them entirely. 

A 33% atomic% of F is detected on electrostatic chuck ceramic surface (high purity alumina) indicating the formation of AlOF on high purity alumina surface under fluorine-containing... 

Fig. 7. A uniform AlOF film (rainbow color) covers the ceramic surface of a used electrostatic chuck after silicon etch processes.

Fig. 8. The ceramic surface of a used electrostatic chuck contains about 33 atom% fluorine on the surface film with a rainbow color.

All the coupons are studied by SEM before and after plasma etching process. The corrosion/erosion rates of different test coupons are recorded and compared as mils per RF hour. Test coupons on etch chamber top window, chamber wall and on electrostatic chuck surfaces are shown in Fig. 9. 

Fig. 9. Test coupons in etching chamber are mounted on chamber top window (left) and on chamber wall (right) and on the dummy aluminum wafer on an electrostatic chuck surface (right, white surface).

Hong Shih, "Method for Refurbishing Bipolar Electrostatic Chuck", Assignee Lam... 

D. Outka and H. Shih, "Surface Analysis of Electrostatic Chuck Surface and Wet... 

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