NOW WE ARE GOING TO POST GUESS PAPER FOR RTU STUDENTS....IT HELPS ONLY THE STUDENT WHO START THEIR STUDY LAST NIGHT.....
IF U R THINKING THAT IT WILL REALLY HELPS U THEN GIVE ME YOUR VIEW ABOUT IT..
THANK YOU
Friday, January 14, 2011
Sunday, January 2, 2011
B.TECH (ELECTRONICS AND COMMUNICATION)- 7th SEM
IC TECHNOLOGY (ELECTRONICS AND COMMUNICATION
1. a) Explain the various defect in crystal? (4)
b) Draw the circuit diagram of float zone growth method and show the four point probe technique
for resistance measurement? (8)
c) Determine the seed and doping and the expected reading at 0.95 fraction solidification for a
boron doped crystal , if it is measured at its ends with a four point probe of spacing 1mm
resulting V/I=10 Ω, Ko= 0.8, Cs=2*10^15 atoms/cm^3. (4)
OR
1. a) Explain the various steps for shaping of crystal obtained from float zone or Cz method? (12)
b) By using equation of Cz and segregation coefficient for oxygen in the crystal at a fraction
solidified of 0.5 .The oxygen concentration at the top of crystal i.e. at X=0.05, Cs=1.3* 10^18
atoms/cm^3? (4)
2. a) prove the continuity equation and fick's second law and briefly explain the kinds of
exchanges? (12)
b) How long could it take for a fixed amount of phosphorous distributed over a surface of 25
micrometer thick silicon wafer to become substantially uniformly distributed throughout wafer
at 1300 degree celsius. Consider that concentration is sufficiently uniform if it does not differ
more than 10 % at the surface.
D = 2.5 * 10 ^ (-12) (4)
OR
2. a) Write the range theory of ion implementation ? (12)
b) What is annealing ? Explain it? (4)
3. a) Define the Vapour Phase Epitaxy method and discuss about the various defects of Epitaxial
growth? (12)
b) What growth velocity will be required to exceed the solid state diffusion of a boron doped
substrate in the time of one minute, if the growth temperature used is 1200 degree celsius?
The diffusion constant of B, at 1200 degree clsius is approximately=10^(-12) cm/sec. (4)
OR
3. a) Draw the neat diagram of MOCVD procss and give the advantages of MBE over CVD? (14)
b) Define Doping and Auto doping? (2)
4. a) What is Lithography? Explain the various step during photo lithographic process? (10)
b) Write down the different stages during development of Photoresist? (6)
OR
4. a) Write the plasma etching process. Also give its advantage over wet etching? (10)
b) Discuss the loading effect? (2)
c) An etch rate of 300 Å/min. has been reported by a plasma etch system for etching a single
wafer .It has been observed that on adding an another wafer to the reactor , etch rate falls to
240 Å/min.Now find out the new respective etch rates for three and four wafer? (4)
5. Write short notes on any TWO:
a) SOI technique (8)
b) LOCOS method (8)
c) Application and problems of metallization. (8)
OR
5. a) If the worst case feature size variation is 0.5µm and worst case misregistration is 0.25 µm for
the features. What is the minimum separation between levels if-
(1) Feature A is aligned to feature B.
(2) Feature A and B are aligned to a third feature. (4)
b) Write down the various fabrication steps for CMOS inverter? (12)
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1. a) Explain the various defect in crystal? (4)
b) Draw the circuit diagram of float zone growth method and show the four point probe technique
for resistance measurement? (8)
c) Determine the seed and doping and the expected reading at 0.95 fraction solidification for a
boron doped crystal , if it is measured at its ends with a four point probe of spacing 1mm
resulting V/I=10 Ω, Ko= 0.8, Cs=2*10^15 atoms/cm^3. (4)
OR
1. a) Explain the various steps for shaping of crystal obtained from float zone or Cz method? (12)
b) By using equation of Cz and segregation coefficient for oxygen in the crystal at a fraction
solidified of 0.5 .The oxygen concentration at the top of crystal i.e. at X=0.05, Cs=1.3* 10^18
atoms/cm^3? (4)
2. a) prove the continuity equation and fick's second law and briefly explain the kinds of
exchanges? (12)
b) How long could it take for a fixed amount of phosphorous distributed over a surface of 25
micrometer thick silicon wafer to become substantially uniformly distributed throughout wafer
at 1300 degree celsius. Consider that concentration is sufficiently uniform if it does not differ
more than 10 % at the surface.
D = 2.5 * 10 ^ (-12) (4)
OR
2. a) Write the range theory of ion implementation ? (12)
b) What is annealing ? Explain it? (4)
3. a) Define the Vapour Phase Epitaxy method and discuss about the various defects of Epitaxial
growth? (12)
b) What growth velocity will be required to exceed the solid state diffusion of a boron doped
substrate in the time of one minute, if the growth temperature used is 1200 degree celsius?
The diffusion constant of B, at 1200 degree clsius is approximately=10^(-12) cm/sec. (4)
OR
3. a) Draw the neat diagram of MOCVD procss and give the advantages of MBE over CVD? (14)
b) Define Doping and Auto doping? (2)
4. a) What is Lithography? Explain the various step during photo lithographic process? (10)
b) Write down the different stages during development of Photoresist? (6)
OR
4. a) Write the plasma etching process. Also give its advantage over wet etching? (10)
b) Discuss the loading effect? (2)
c) An etch rate of 300 Å/min. has been reported by a plasma etch system for etching a single
wafer .It has been observed that on adding an another wafer to the reactor , etch rate falls to
240 Å/min.Now find out the new respective etch rates for three and four wafer? (4)
5. Write short notes on any TWO:
a) SOI technique (8)
b) LOCOS method (8)
c) Application and problems of metallization. (8)
OR
5. a) If the worst case feature size variation is 0.5µm and worst case misregistration is 0.25 µm for
the features. What is the minimum separation between levels if-
(1) Feature A is aligned to feature B.
(2) Feature A and B are aligned to a third feature. (4)
b) Write down the various fabrication steps for CMOS inverter? (12)
♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦
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