Manufacturing method of a silicon wafer having a controlled BMD concentration
AssigneeToshiba Ceramics Co., Ltd.
InventorsKenro Hayashi, Ryuji Takeda, Katsuhiro Chaki, Ping Xin, Jun Yoshikawa, Hiroyuki Saito
Life of this patent
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Abstract
In a heat history initializing step, a heat treatment in performed in an atmosphere including at least one of hydrogen, helium, and argon while the temperature is increased in a range of 700.degree. C. to 1,000.degree. C. at a rate of 15.degree.-1,000.degree. C./min. In a controlled nuclei growing step, a heat treatment is performed in the above atmosphere while the temperature is kept constant in a range of 850.degree. C. to 980.degree. C. for 0.5-60 minutes.
Claims11
A method of manufacturing a silicon wafer, comprising the steps of:
- initiating a heat history of a wafer produced from a single crystal silicon ingot, the heat history being a heat treatment in which the wafer is heated in an atmosphere including at least one of hydrogen, helium, and argon, while a wafer temperature is increased in a range of 700.degree.-1000.degree. C., at a rate not lower than 15.degree. C./min to thereby control a concentration of ultra-small oxygen deposits;
- and
- controlling the growth of re-deposition nuclei.
A method of manufacturing a silicon wafer, comprising the steps of:
- placing a wafer produced from a single crystal silicon ingot into a furnace;
- increasing a wafer temperature in a range of 800.degree. C. to 1,000.degree. C. at a first rate of 15.degree. to 1,000.degree. C./min;
- and
- increasing the wafer temperature in a range of 1,000.degree. C. to 1,300.degree. C. at a second rate lower than said first rate and in the range of 0.5.degree.-1.degree. C./min;
- and
- keeping the wafer temperature constant in a range of 1,100.degree. C. to 1,300.degree. C. for not less than 5 minutes.
A method of manufacturing a silicon wafer, comprising the steps of:
- preparing a silicon wafer having an interstitial oxygen concentration of 1.4-1.8.times.10.sup.18 atoms/cm.sup.3 ;
- placing the silicon wafer in a furnace;
- filling the furnace with an atmosphere including at least one of hydrogen and an inert gas;
- increasing a wafer temperature at a first rate of 15.degree. to 100.degree. C./min in a range of a room temperature to 900.degree. C. and at a second rate lower than said first raten, said second rate being 1.degree. to 15.degree. C./min in a range of 900.degree. C. to a holding temperature;
- and
- keeping the wafer temperature at the holding temperature that is in a range of 1,100.degree. C. to 1,300.degree. C. for 1 minute to 48 hours.
Dependencies are inferred from the claim text.