Reducing radioactive decay time of phosphorus doping in silicon - produced using thermal neutrons by optimising flux density and time,申请号DE19762615324-传众专利搜索

Reducing radioactive decay time of phosphorus doping in silicon - produced using thermal neutrons by optimising flux density and time

申请公布号：DE2615324(A1)

申请号：DE19762615324

申请日期：1976.04.08

申请公布日期：1977.10.27

申请人：

SIEMENS AG

发明人：HAAS,ERNST;MARTIN,JOACHIM

分类号：C30B31/18;H01L21/261;(IPC1-7):B01J17/34;B01J17/40

主分类号：C30B31/18

摘要：<p>Reducing the radioactive decay time of the activity resulting from the irradiation of Si crystals with thermal neutrons to produce homogeneous P doping by the reactions 3oSi (n, gamma)31 Si beta -31P(n, gamma) beta -32 P(sic) involves selecting the prod of the thermal neutron flux density and the irradiation time (t)for the desired P doping in the Si per unit amt. of Si so that circle with diagonal line is adjusted to its optimum value w.r.t. the min calculated 32P activity value (S), according to the mathematical formula derived for the formation of the 32p activity. The 32P activity is reduced or altered so that doping can be carried out with up to 100 times the amt. of Si. For high resistivity (e.g. 100 ohm. cm), t is small and for low resistivity (0.1-10 ohm.cm) t is large. E.g. for doping to a resistivity of 100 ohm.cm. if t =69.4 h, circle with diagonal line = 1012 cm2 s-1 and S=6.8 x 10-3 mu Ci/kg Si, whereas if t=0.694h, circle with diagonal line = 1014 cm2 s-1 and S=4.55 x 104 mu Ci/kg Si.</p>