MCQOPTIONS
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MCQOPTIONS
This section includes 24 Mcqs, each offering curated multiple-choice questions to sharpen your Vlsi knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
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 |
| Answer» E. | |
| 2. |
Gate oxide layer consists of ___________ |
| A. | SiO2 layer, overlaid with a few layers of an oxynitrided oxide |
| B. | Only SiO2 Layer |
| C. | SiO2 layer with Polysilicon Layer |
| D. | SiO2 layer and stack of epitaxial layers of Polysilicon |
| Answer» B. Only SiO2 Layer | |
| 3. |
Chemical Mechanical Polishing is used to ___________ |
| A. | Remove silicon oxide |
| B. | Remove silicon nitride and pad oxide |
| C. | Remove polysilicon gate layer |
| D. | Reduce the size of the layout |
| Answer» C. Remove polysilicon gate layer | |
| 4. |
Which process is involved in growing the shaded region?a) Chemical vapor deposition (CVD)b) Sputtering and patterned by etchingc) Chemical vapor deposition (CVD) and patterned by HF acid etchingd) Chemical vapor deposition (CVD) and patterned by dry (plasm |
| A. | Chemical vapor deposition (CVD) |
| B. | Sputtering and patterned by etching |
| C. | Chemical vapor deposition (CVD) and patterned by HF acid etching |
| D. | Chemical vapor deposition (CVD) and patterned by dry (plasma) etching |
| Answer» E. | |
| 5. |
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 |
| Answer» B. Chemical vapour deposition | |
| 6. |
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 |
| Answer» C. Silicon oxide | |
| 7. |
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 |
| Answer» E. | |
| 8. |
The chemical used for shielding the active areas to achieve selective oxide growth is? |
| A. | Silver Nitride |
| B. | Silicon Nitride |
| C. | Hydrofluoric acid |
| D. | Polysilicon |
| Answer» C. Hydrofluoric acid | |
| 9. |
The isolated active areas are created by technique known as ___________ |
| A. | Etched field-oxide isolation |
| B. | Local Oxidation of Silicon |
| C. | Etched field-oxide isolation or Local Oxidation of Silicon |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 10. |
The ______ is used to reduce the resistivity of poly silicon. |
| A. | Photo resist |
| B. | Etching |
| C. | Doping impurities |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 11. |
Positive photo resists are used more than negative photo resists because ___________ |
| A. | Negative photo resists are more sensitive to light, but their photo lithographic resolution is not as high as that of the positive photo resists |
| B. | Positive photo resists are more sensitive to light, but their photo lithographic resolution is not as high as that of the negative photo resists |
| C. | Negative photo resists are less sensitive to light |
| D. | Positive photo resists are less sensitive to light |
| Answer» B. Positive photo resists are more sensitive to light, but their photo lithographic resolution is not as high as that of the negative photo resists | |
| 12. |
Silicon oxide is patterned on a substrate using ____________ |
| A. | Physical lithography |
| B. | Photolithography |
| C. | Chemical lithography |
| D. | Mechanical lithography |
| Answer» C. Chemical lithography | |
| 13. |
What is Lithography? |
| A. | Process used to transfer a pattern to a layer on the chip |
| B. | Process used to develop an oxidation layer on the chip |
| C. | Process used to develop a metal layer on the chip |
| D. | Process used to produce the chip |
| Answer» B. Process used to develop an oxidation layer on the chip | |
| 14. |
Chemical Mechanical Polisihing is used to:$ |
| A. | Remove silicon oxide |
| B. | Remove silicon nitride and pad oxide |
| C. | Remove polysilicon gate layer |
| D. | Reduce the size of the layout |
| Answer» C. Remove polysilicon gate layer | |
| 15. |
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 |
| Answer» E. | |
| 16. |
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 |
| Answer» B. Chemical vapour deposition | |
| 17. |
To grow the polysilicon gate layer, the chemical used for chemical vapour deposition is: |
| A. | Silicon Nitride(Si4N3) |
| B. | Silane gas(SiH4 ) |
| C. | Silicon oxide |
| D. | None of the mentioned |
| Answer» C. Silicon oxide | |
| 18. |
The dopants are introduced in the active areas of silicon by: |
| A. | Diffusion process |
| B. | Ion Implantaion process |
| C. | Chemical Vapour Deposition |
| D. | Either Diffusion or Ion Implantaion Process |
| Answer» E. | |
| 19. |
The chemical used for shielding the active areas to achieve selective oxide growth is: |
| A. | Silver Nitride |
| B. | Silicon Nitride |
| C. | Hydrofluoric acid |
| D. | Polysilicon |
| Answer» C. Hydrofluoric acid | |
| 20. |
The isolated active areas are created by technique known as: |
| A. | Etched field-oxide isolation |
| B. | Local Oxidation of Silicon |
| C. | Both the mentioned |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 21. |
The ______ is used to reduce the resistivity of poly silicon: |
| A. | Photo resist |
| B. | Etching |
| C. | Doping impurities |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 22. |
Positive photo resists are used more than negative photo resists because: |
| A. | Negative photo resists are more sensitive to light, but their photo lithographic resolution |
| B. | |
| Answer» B. | |
| 23. |
Silicon oxide is patterned on a substrate using: |
| A. | Physical lithography |
| B. | Photolithography |
| C. | Chemical lithography |
| D. | Mechanical lithography |
| Answer» C. Chemical lithography | |
| 24. |
Lithography is: |
| A. | Process used to transfer a pattern to a layer on the chip |
| B. | Process used to develop an oxidation layer on the chip |
| C. | Process used to develop a metal layer on the chip |
| D. | Process used to produce the chip |
| Answer» B. Process used to develop an oxidation layer on the chip | |