After cleaning in Piranha (H2SO4 + H2O2 at 120 C), I measured contact angles of 0 deg for samples of SiO2 and Si3N4 deposited by different means. The contact angle stayed low for a few days, but gradually increased over time from contamination in the atmosphere while stored in a standard wafer shipping container. --Kirt Williams ----- Original Message ----- From: "Pradeep Dixit"To: "General MEMS discussion" Sent: Friday, December 02, 2005 9:12 AM Subject: [mems-talk] Contact angle of Silicon and SiO2 > Hi all, > > Can any one let me know what is the normal contact angle of silicon, thermal > grown SiO2 and LPCVD Si3N4 layer with water ? > > After surface treatment like SC1 and RCA cleaning, how much it can > be reduced ?