Abstract
Newly released roots type dry vacuum pumps (PDR-C series; ULVAC JAPAN, Ltd.) are described.
Main parts of the pumps consist of aluminum cast alloys. Their high thermal conductivity makes it easy to regulate operation temperature by changing cooling water path. These models have high and low temperature operation modes.
High temperature operation (>120°C) are suitable for Si3N4 CVD, NF3 cleaning and low temperature operation (<100°C) for Cu-CVD, W-CVD processes.
