450mm PVD MHM TiN process development and process chamber evaluation using DC power system

Abstract

There are many excellent film properties of Titanium Nitride, such as high hardness, high corrosion resistance, good conductivity, low friction coefficient and a bright, golden color. In the past couple of years, it has been always used as barrier layer to inhibit diffusion of Al and Cu. In the most advance technology nodes, such as 20 nm, 16 nm and below, the metal hard mask (MHM) layer is necessary for better etching profile and less PR budget. Titanium Nitride has been used in BEOL (back-end of line) as MHM because of its film properties. In 450mm generation, cost saving and good productivity are the most important key factors. In this generation, we use DC power system as process chamber, and increase DC power to improve deposition rate. It will be a win-win approach to improve productivity and reduce cost. However, increasing DC power will transit stress in TiN to high compressive level. It will induce pattern wiggling. On the other hand, the U% of thickness is also considered at the same time. Faster deposition rate always induce worse U%. In order to get the best productivity and still have good stress and thickness U%, we study some solutions to develop 450mm PVD MHM TiN process and chamber evaluation by using DC power system.