3.1551/6152 Homework set 3 solution. fall 2003 0.3 0.2 0.1 x10-05 x10-06 10 4x106 2x106 Problem 5 At 30 keV, from Fig 8-3, R, 2 120 nm and AR= 50 nm. Given 0= 10cm=0.01 nm a) Peak occurs at depth where x=R, 120 nm b) From Eq.84,Cn=8×10°nm3=8×10°cm3 c)Atx=300nm,Eq.8.1 gives c=1.23×107nm3=1.23×104cm d) If the dose at 0.3 microns is 10 times larger than this even though the values of R, and C, are correct, then the wafer was not pure, but rather doped with boron to1.1×105cm3(1.11×103+1.23×104+=103.155J/6.152J Homework set 3 solution, fall 2003 3 Problem 5 At 30 keV, from Fig. 8-3, Rp ≈ 120 nm and DRp ≈ 50 nm. Given Q= 1012 cm-2 = 0.01 nm-2. a) Peak occurs at depth where x = Rp ≈ 120 nm. b) From Eq. 8.4, Cp = 8 ¥ 10-5 nm-3 = 8 ¥ 1016 cm-3. c) At x = 300 nm, Eq. 8.1 gives Cp = 1.23 ¥ 10-7 nm-3 = 1.23 ¥ 1014 cm-3. d) If the dose at 0.3 microns is 10 times larger than this even though the values of Rp and Cp are correct, then the wafer was not pure, but rather doped with boron to 1.1 ¥ 1015 cm-3 (1.11 ¥ 1015 + 1.23 ¥ 1014 = 10 ¥