N-type buried layer drive-in recipe to reduce pits over buried antimony layer

A method of driving-in antimony into a wafer, including the steps of:

• loading a wafer into an annealing furnace/tool;
• the wafer having an area of implanted antimony ions;
• annealing the wafer a first time at a first temperature in the presence of only a first nitrogen gas flow rate;
• growing an oxide layer over the wafer during:
• ramping-down of the wafer from the first temperature to a second temperature in the presence of only an oxygen gas flow rate;
• maintenance of the wafer in the presence of the oxygen gas flow rate at the second temperature;
• and
• ramping-up of the wafer from the second temperature to a third temperature in the presence of only the oxygen gas flow rate;
• annealing the wafer a second time at the third temperature in the presence of only a second nitrogen gas flow rate to drive-in the antimony ions within the area of implanted antimony.

A method of driving-in antimony into a wafer, including the steps of:

• A. loading a wafer into an annealing furnace/tool;
• the wafer having an area of implanted antimony ions;
• the area of implanted antimony ions having an antimony ion concentration of from about 1 E 15 to 5 E 15 ions/cm3;
• B. annealing the wafer a first time at a first temperature in the presence of only a first nitrogen gas flow rate;
• the first temperature being from about 985 to 1015° C.;
• C. ramping-down the wafer from the first temperature to a second temperature in the presence of only an oxygen gas flow rate;
• the second temperature being from about 885 to 915° C.;
• D. maintaining the wafer in the presence of the oxygen gas flow rate in the absence of hydrogen at the second temperature;
• E. ramping-up the wafer from the second temperature to a third temperature in the presence of only the oxygen gas flow rate;
• the third temperature is from about 1185 to 1215° C.;
• and
• F. annealing the wafer a second time at the third temperature in the presence of only a second nitrogen gas flow rate to drive-in the antimony ions within the area of implanted antimony.

A method of driving-in antimony into a wafer, including the steps of:

• A. loading a wafer into an annealing furnace/tool;
• the wafer having an area of implanted antimony ions;
• B. annealing the wafer a first time at a first temperature in the presence of only a first nitrogen gas flow rate;
• C. forming an oxide layer over the implanted antimony ion area using dry oxidation processes at a second and third temperatures;
• and
• D. annealing the wafer at the third temperature in the presence of only a second nitrogen gas flow rate to drive-in the antimony ions within the area of implanted antimony.