Production proven electrostatic platen for medium current implantation

Abstract

Abstra,ct-Electrostatic wafer platens (ESPs) for ion implant systems offer enormous benefits in manufacturing productivity. This paper describes and compares the performance of the standard clamp in current use in more than 50 user sites with a new cooled platen design. As would be expected the ESP platens do not affect dosing, charging, or front side particulates. Device damage from the ESP is not an issue because of the safe AC operating mode. Cooling performance of 1 watt/cm* for 200mm wafers using nitrogen as the cooling gas has been obtained. Tests indicate that backside particles are dependent on the surface smoothness of the platen and the smoothness of the back side of the wafer being clamped.uses a six sector electrode configuration with three phase operation. The electrode configuration is a bit more complex as explained below and the dielectric is a single circular sheet of alumina, but otherwise the design and operation are the same as the six segment design. The one piece dielectric design allows low leakage gas cooling operation. In fact, with gas cooling the newer platen is capable of providing more than 1 watt/cm2 of cooling with a wafer temperature not exceeding 100" C. PLATEN DESIGN FEATURES

Impact of back side defects on feol processes and yield

“…Several studies of back side defectivity have been previously reported in the literature. [1][2][3][4][5][6][7][8][9][10] The majority of processing equipment for IC devices utilize single wafer processing for Etch, Photolithography, CVD, PECVD, and Polish operations. Yet, Diffusion and Wet Clean processes are typically performed in batches and are susceptible to defect transfer between wafers during processing.…”