1. The dopants are introduced in the active areas of silicon by using which process?
a) Diffusion process
b) Ion Implantation process
c) Chemical Vapour Deposition
d) Either Diffusion or Ion Implantation Process
Explanation: Two ways to add dopants are diffusion and ion implantation.
2. To grow the polysilicon gate layer, which of the following chemical is used for chemical vapour deposition?
a) Silicon Nitride(Si3N4)
b) Silane gas(SiH4)
c) Silicon oxide
d) None of the mentioned
Explanation: Silicon Wafer is placed in a reactor with silane gas (SiH4), and they are heated again to grow the polysilicon layer by chemical vapor deposition
3. The process by which Aluminium is grown over the entire wafer, also filling the contact cuts is?
a) Sputtering
b) Chemical vapour deposition
c) Epitaxial growth
d) Ion Implantation
Explanation: Aluminum is sputtered over the entire wafer, it also fills the contact cuts.
4. What is Piranha Solution?
a) It is a 3:1 to 5:1 mix of nitric acid and hydrogen peroxide that is used to develop the oxide layer on silicon substrate
b) It is a 3:1 to 5:1 mix of sulphuric acid and hydrofluoric acid that is used to clean silicon wafers removing organic and metal contaminants or photo resist after metal patterning
c) It is a 3:1 to 5:1 mix of sulphuric acid and hydrogen peroxide that is used to grow the oxide layer on the silicon
d) It is a 3:1 to 5:1 mix of sulphuric acid and hydrogen peroxide that is used to clean wafers of organic and metal contaminants or photo resist after metal patterning
Explanation:Piranha solution is a 3:1 to 5:1 mix of sulfuric acid and hydrogen peroxide that is used to clean silicon wafers of metal and organic contaminants or photo-resist after metal patterning.
5. Ids depends on ___________
a) Vg
b) Vds
c) Vdd
d) Vss
Explanation: Ids depends on both Vgs and Vds. The charge induced is dependent on the gate to source voltage Vgs also charge can be moved from source to drain under influence of electric field created by Vds.
6. Ids can be given by __________
a) Qc x Ʈ
b) Qc / Ʈ
c) Ʈ / Qc
d) Qc / 2Ʈ
Explanation: Ids can be given as charge induced in the channel(Qc) divided by transit time (Ʈ). Ids is equivalent to (-Isd)
7. Transit time can be given by __________
a) L / v
b) v / L
c) v x L
d) v x d
Explanation:Transit time (Ʈ) can be given by lenght of channel(L) by velocity(v). Transit time is the time required for an electron to travel between two electrodes.
8. Velocity can be given as __________
a) µ / Vds
b) µ / Eds
c) µ x Eds
d) Eds / µ
Explanation: Velocity can be given as the product of electron or hole mobility(µ) and electric field(Eds). It gives the flow velocity which an electron attains due to electric field.
9. Eds is given by __________
a) Vds / L
b) L / Vds
c) Vds x L
d) Vdd / L
Explanation: Electric field(Eds) can be given as the ratio of Vds and L. Eds is the electric field created from drain to source due to volta Vds.
10. What is the mobility of proton or hole at room temperature?
a) 650 cm2/V sec
b) 260 cm2/V sec
c) 240 cm2/V sec
d) 500 cm2/V sec
Explanation: The value of mobility of proton or hole at room temperature is 240 cm2/V sec. This gives the measure of how fast an electron can move