AVS 46th International Symposium
    Manufacturing Science and Technology Group Monday Sessions
       Session MS-MoA

Paper MS-MoA8
Minimizing Particle Generating Contamination in Polysilicon LPCVD

Monday, October 25, 1999, 4:20 pm, Room 611

Session: Ultra-Clean Society and Contamination Free Manufacturing
Presenter: J. Krueger, Texas Instruments Incorporated
Authors: J. Krueger, Texas Instruments Incorporated
J. Snow, Millipore Corporation
J. Hardin, Millipore Corporation
J. Gratz, Millipore Corporation
Correspondent: Click to Email
Increasing wafer size and decreasing critical dimensions exacerbate the chances of a particle coming to rest in a die-killing location. In this study, the effect of point-of-use (POU) purification was evaluated by processing two sets of split lot wafers on an LPCVD polysilicon horizontal furnace. The gas quality downstream of the furnace was evaluated using a closed ion source (CIS) residual gas analyzer (RGA) and an in-situ particle counter (ISPM). Wafer particle counts, film contamination levels by secondary ion mass spectroscopy (SIMS), surface roughness and grain size measurements by atomic force microscopy (AFM) were all used to compare the split lot halves processed with and without purification. SIMS analysis showed that oxygen levels in the film were lower for wafers run with the purifiers. Also, secondary ion counts of silicon were slightly higher in the film of the wafers processed with the purifiers. Wafer particle data showed that wafers run with the purifiers had 72% fewer added defects. The ISPM sensor showed that there were 37% fewer particles with the purifiers in place. RGA results revealed lower moisture levels with the purified silane deposition step compared to unpurified.