Thermal budget consideration in rapid isothermal processing

Abstract

Rapid isothermal processing (RIP) based on incoherent radiation as the source of thermal and optical energy is emerging as a key low-thermal budget processing technique. Because of high heating and cooling rates, the RIP cycle generally refers to processing time and temperature. In this letter, we have shown that the properties of materials and devices fabricated by RIP depends on the heating and cooling rates. Optimized heating and cooling rates can minimize unwanted phenomena (e.g., higher thermal stress, warpage, etc.) leading to the improved performance of the devices fabricated by RIP. To demonstrate this significance of heating and cooling rates, we report the wafer dimensional analysis results for ramp rates of 15, 75, 100, 150, and 200 °C per second at a maximum steady-state temperature of 1050 °C. Plasma and low-pressure chemical vapor deposition silicon nitride films on 6-in. wafers were studied for warpage. The BF2 and As implanted wafers at a fixed dose of 8×1015/cm2 were studied for slow (15 °C per second) and fast (200 °C per second) ramp rates. We also present stress, secondary ion mass spectroscopy, and diode leakage current results for different RIP cycles of interest.