Implant Angle Deviation Reduction in Batch-Type High Energy Implanter

Angle deviations at zero-degree implants are very large with an ordinary disk, which has a cone angle of 5 degrees. Dopant depth profiles are different within a wafer due to the angle deviations since the channeling at zero-degree is very steep. To achieve more uniform dopant depth profiles at zero-degree implants, the NV-GSD-HE3/RD (RD), which has a process disk with a small cone angle of 1.5 degrees, was developed. Using the reduced cone angle disk, the angle deviations at zero-degree implants are reduced to 1/3 of those with the ordinary disk, improving drastically the uniformity of dopant depth profiles within a wafer.