Study of 7V Device Application based on 0.18um Platform Process

Abstract

In conventional 0.18um and following CMOS process platforms, the 5V device is a very familiar device, With the diversification of the market, conventional 5V devices are now being used more and more at 7V or 8V voltages. Can get high breakdown voltage characteristic and low conduction resistance, in the market is more competitive. In this paper, the 5V device breakdown characteristic of 0.18um platform is analyzed, because the LDD implant to pass through the poly, cannot be high-energy implant, the junction depth is relatively shallow, the lateral diffusion is relatively small. In the breakdown state, because the poly edge electric potential line is relatively concentrated, and the LDD light doped area is short, the depletion region is narrow, causing strong electric field, therefore, the improvement of breakdown voltage is a difficult problem when the 5V device is applied to the 7V, 8V voltage. This paper mainly analyzes the method of developing 7V, 8V device on 5V platform, by putting LDD implant in front of poly, breaking the limit of implant energy, and adjusting the width of LDD and poly overlap at will, to adjust the breakdown voltage and conduction resistance of the device, to meet the application of different markets.