{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

chapter-9-solutions

# chapter-9-solutions - Chapter 9 Prob 9.1 Relate the sheet...

This preview shows pages 1–3. Sign up to view the full content.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Chapter 9 Prob. 9.1 Relate the sheet resistance of a diﬁused layer to Nah) and 3,3. (9) 1 R _____ 5 31' (00¢: (a) = x1 0:, ppNa dz: , if N.,(x) >> Nd over most of the proﬁle 1 R, = [q [0” mmm 4] M For a 200 Q/square diﬂ’usion, ﬁnd the aspect ratio for a 10 1:9 resistor, and draw a diﬁusion pattern for a width of 5pm. R = R,L/W, thus L/W = 10‘/200 = 50 For W = 5 mm, L :25!) pm. 130 130 Prob. 9.3 .4 boron isolafz'on dzﬁusimz (I) z: 2.5 >< 10‘”. No : 102”) penetnzies a 311m epitaxial layer with N4 2: 1015. (a) Wth diﬂuswn time is required ‘5’ {b} How far would an Sta-doped buried layer ()9 :- ‘3 x ‘10“‘3‘ No -.- 102°) more during this diffusion .9 (a) N(x,2) = N0 erfc 2‘2)? We want, N(5‘x10",i) m: 1016 cm'3 3 x 10" 1016 r: 1020 erfc w 2\/2.5 x 10*”? , 1016 cm: u “—- 3—6-23 = 10“, u ’2: 2.75 from Fig. 1’5 —~ 2 30 300 2.75 m 3.150ﬁ , W s:— W , in 1192 seconds (1)) For Dz‘ZXlO‘m, u: 16 erfcu 2 11—2-23 :10“, u 2.75 Thus, :3 = -—-——-——-— 2 3.24 x 10‘ I - _( .~__ 4 W““m° = 2.75 (185 mm 131 Prob. 9.4 For the given p-type wafer with 4-point probe measurements on the doped and undoped part of the wafer being used. ﬁnd the measured sheet resistance in the undoped part. Calculate the average resistivity If we have a sheet resistance of 90 ohmsésquare in the doped part. Find the temperature at which the P diﬂiuion was done. R52 RS] '- t = 500m: NM, =10‘5cm'3, R5, in undoped pan = P— : ————-!-§——— : 3000/ square tn undoped part, 5 = R52 ~x = 90 (0.8 x10") = 0.00729cm = 729nm. From solid solubility curve for P (App. VII), if P concentration == 6 x 102° (ms, '1‘ = 900°C. If P concentration = 6 x 1019 cm‘3, extrapolating the curve, T = 700°C. 132 132 ...
View Full Document

{[ snackBarMessage ]}

### Page1 / 3

chapter-9-solutions - Chapter 9 Prob 9.1 Relate the sheet...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online