Temperature distribution in semiconductor wafers arranged in a row at insertion into a diffusion furnace.

The transient radial temperature distribution in circular wafers arranged in a row was numerically calculated as the wafers were inserted into a high-temperature diffusion furnace. Radiation heating of specular wafers and unsteady heat conductions in the wafers were combined. The calculated temperature change agreed with the experimental results when the temperature was higher than 700°C. Relations between the transient temperature distribution in the wafers and the dimensionless parameters, which consisted of the wafer radius, thickness, spacing, and insertion speed, were calculated systematically when the wafers were inserted into a 1 000°C furnace. The temperature distribution was maximizing when the wafer spacing was about 10 % of the wafer radius. Thin and large wafers had large temperature distributions. Temperature distribution decreased when the insertion speed was less than a critical dimensionless value.