Novel reactor design configuration for contamination control and improved performance in the polysilicon doping process using POCl sub(3)

• Published in: Journal of the Electrochemical Society Vol. 141; no. 8; pp. 2257 - 2262
• Main Authors: Roy, Sudipto R, Glynn, Phil, Hogan, Rod, Reynolds, Jeff
• Format: Journal Article
• Language: English
• Published: 01.01.1994
• ISSN: 0013-4651

Conventional POCl sub(3) reactors have process limitations because of the hazardous nature of process by-products. Experiments were conducted using a novel design quartz flange and stainless steel clamp exhaust configuration, along with a scavenger insulation block, which eliminated process by-product buildup inside the reactor tube in the scavenger area. Experiments included variations in doping temperature, process time, POCl sub(3) flow rate, and carrier and exhaust gas flow rates. This novel super(e) hardware design practically eliminates by-product condensation and dripping outside the reactor, which reduces cross-contamination and stainless steel corrosion problems and prevents potential minority carrier lifetime degradation. Equipment downtime is significantly reduced by eliminating autodoping and the need for frequent process tube steam cleans. Run capability is extended because of the new design, which also provides superior exhaust control and safer operation. The design also allows doubling of the number of wafers processed with improved sheet resistance uniformity. Regression equations were obtained for calculating sheet resistance, which can be a viable tool for process engineers. The new reactor configuration provides significant advantages in reduced equipment downtime, increased savings in material, and improved process performance.