Chemical vapour deposition of Si3N4 from a gas mixture of Si2Cl6, NH3 and H2

Abstract

Si3N 4 layers were obtained on a quartz substrate from a gas mixture of Si2CI6, NH3 and H2 under a reduced pressure in a temperature range of 800 to 1300 ~ C. Amorphous Si3N 4 layers that were dense and adherent to the substrate were obtained in a temperature range of 800 to 1100 ~ On the other hand, ~-Si3N4 layers were obtained at 1200~ and a source-gas ratio (N/Si) of 1.33 to 1.77. The lowest deposition temperature of amorphous Si3N 4 was considered to be about 700 ~ C. The microhardness of amorphous Si3N, obtained in a temperature range of 800 to 1100~ was 2400 to 2600kg mm -2 (load: 50g), and that of ~-Si3N4 obtained at 1200~ was 3400 kg mm -2. Chlorine contents in the Si3N4 layer decreased with increasing deposition temperature and source-gas ratio (N/Si), and with decreasing total pressure.

Thermal Chemical Vapor Deposition of Bis(Tertiary-Butylamino)Silane-based Silicon Nitride Thin Films

“…Among several potential candidates for low-temperature silicon nitride CVD, bis͑tertiary-butylamino͒silane ͑BTBAS͒, and hexachlorodisilane ͑HCD͒ have gained acceptance in semiconductor manufacturing, with processing thermal budgets of 4-6 h at ϳ600°C. [4][5][6][7][8][9] Batch furnaces that utilize HCD and NH 3 as nitride precursors suffer from NH 4 Cl formation and related issues, and safety related issues due to the highly reactive and hazardous chemical ͑HCD͒. Furnace systems that use BTBAS and NH 3 as nitride precursors suffer from residue deposition on certain parts of the furnace, which peel due to high stress of the nitride film, and deposit foreign matter on the wafer.…”