Vacuum Trench Filling Process for Semiconductor and Packaging Device Fabrication
Original Publication Date: 1985-Mar-01
Included in the Prior Art Database: 2005-Feb-18
A wafer 10, with isolation trenches thereon, is to be filled with a viscous, high molecular weight polyimide material (such as DuPont's RC-5878) which will not fill trenches formed in substrates under usual processing conditions. The polymer is dispensed into a vacuum chamber 11 to eliminate the voids and bubbles which prevent gap trench filling. The wafer 10 rests on a stainless steel base 9. The wafer is covered by a vacuum chamber 11, sealed by O-ring 8, which rests on base 9. The chamber 11 containing the workpiece 10 is evacuated with line 21 to vacuum pump line 24. A vacuum of about 10 micrometers is drawn by line 21 with a bleed inlet 22 and stopcocks 23 to remove gas from chamber 11 to facilitate the filling of the trench. Polymer 14 is stored in reservoir 15 which is heated by temperature control jacket 16.