Specific Process Knowledge/Thermal Process/A3 Phosphor Drive-in furnace

A3 Furnace Phosphorus drive-in

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A3 phosphorus drive-in furnace: positioned in cleanroom 2

A3 Furnace phosphorus drive-in is a Tempress horizontal furnace for oxidation of silicon wafers, annealing of the grown oxide, drive-in of phosphor after a pre-deposition. Phospher pre-deposition takes place in the A4 Furnace phosphorus pre-dep. A3 can also be used for drive in of phosphor which has been ion implanted.

A3 is the third furnace tube in the A-stack positioned in cleanroom 2. The A-stack together with furnace C1 are the cleanest of all our furnaces. Please be aware of which substrates are allowed to enter this furnace. Check the cross contamination chart. If you are in doubt, please ask one from the furnace team.

Process knowledge

• Phosphorus drive-in: look at the Dope with Phosphorus page
• Oxidation: look at the Oxidation page
• Annealing: look at the Annealing page

Overview of the performance of the phosphorus drive-in furnace and some process related parameters

Purpose	Drive-in of phosphor, oxidation of silicon and annealing of the oxide.	Oxidation: Dry Wet: with torch (H2+O2)
Performance	Film thickness	Dry SiO2: 50Å to ~2000Å (takes too long to make it thicker) Wet SiO2: 50Å to ~3µm ((takes too long to make it thicker)
Process parameter range	Process Temperature	800-1150 oC
	Process pressure	1 atm
	Gasses on the system	O2, N2 and H2
Substrates	Batch size	1-30 4" wafer (or 2" wafers) per run
	Substrate material allowed	Silicon wafers (new from the box or RCA cleaned) From A4 furnace directly (e.g. incl. Predep HF) In doubt: look at the cross contamination sheet or ask one from the furnace team