Variable cell projection as an advance in electron-beam cell projection system

摘要

As an advance in the electron-beam cell projection system, we have developed a deflection control and correction unit of the variable cell projection (VCP) system, which can increase the variety of projected images through a block of patterns on a CP mask. We estimate the extent of the minimum spacing between two patterns distinguished by partial illumination to be 58 nm on a wafer, which is due to the beam blur of 28 nm and the illuminating beam edge rotation of 6 mrad relative to the CP mask patterns. Exposure results show that the VCP can actually distinguish the patterns separated by 80 nm on a wafer. We also show that the VCP can improve the uniformity of linewidths of exposed patterns by about 5 nm compared with the simple VSB method.