Standard Pre-Diffusion Clean for Oxidation (SC1/HF dip/SC2) of Non-Metal Wafers (clean)

This process module describes cleaning of non-metal Si or Quartz (fused silica) wafers before loading into tools from the “clean” equipment group.

Clean for Oxidation

Purpose:

 A three step cleaning process is used to remove 1) any surface organic material, 2) any native oxide and 3) any trace metals that may be on the surface of the wafers.  This clean leaves the wafer surface clean of any mobile ions in preparation for high temperature processing.

Equipment:

Wbclean-1 and -2

Time of Execution:

Approximately one hour.

Step Summary:

Step 1, SC1

time = 10:00 minutes

temperature = 50°C

chemical = 5:1:1 H2O:H2O2:NH4OH

dump rinse

Step 2, HF dip

time = 30 seconds

temperature = room temp

chemical = 50:1 HF

dump rinse

Step 3, SC2

time = 10:00 minutes

temperature = 50°C

chemical = 5:1:1 H2O:H2O2:HCl

dump rinse

spin dry

NOTE: the wafers must be re-cleaned if they have not been loading into an oxidation furnace within one hour of being cleaned.

Detailed Procedure:

Please see operating instructions for wbclean-1 and -2.