HMDS/image reversing oven is a vacuum oven which allows vapor treatment of substrates in elevetad temperature and low vapor pressure. Oven was dedicated only for HMDS but after modifications is also capable to perform image reversing process = changing an exposed positive resist into a negative resist.
Process 1. HMDS improving resist adhesion to Si an SiO2 (mainly); temperature 110°C, PRG 0; 5min exposure to HMDS vapor at pressure around 7-10Torr
Process 2. Image reversing (positive to negative) by exposure to NH3 vapor; temperature 90°C, PRG 2, 45min exposure to NH3 vapor at pressure arounf 600Torr