VLSI Fabrication Technology (INDSE7D) — DU B.Sc. (Hons) Instrumentation Previous Year Question Papers

Q. 4(a) a) (c) Explain how rapid thermal armealing qiTA) helps in dopant activation and defect repair. (4) Q. 5(a) Summarize the wafer fabrication sequence from substrate cleaning to (7) Explain stamp-based printing and Laser transfer pattern transfer methods (7) used in fabrication process. What is meant by Advanced Process Integration? (4) Q. 6(a) Explain the electron beam evaporation technique used for thin film (7) (b) What is Reactive Ion Etching (RIB) process? Explain its advantages over (7) other available etching processes. (c) wihat are different sources of contamination in clean room? (4) Q. 7 (a) What are the different Ion Implantation techniques used in semiconductor (7) fabrication? Explain any two of them. Explain Atomic Layer Deposition (ALD) technique used for thin film (7) deposition along with its advantages over other available techniques. What are.Multiple Patterning and Self-Alignment techniques in advanced (4) VLSI Fabrication Technology B.Sc. (H) Instrumentation (DSE) Q1.(a) (b) (c) (d) (e) (I) What is the principle behind Interference lithography? What are the main stages in the evolution from ssl to VLSI? Differentiate between wet oxidation and dry oxidation of silicon. Differentiate between positive and negative photoresist in the lithography process. What is sputtering? Explain its basic working principle. Define photomask and reticle. How do they differ? (c) Explain how Moore's Law has driven advanced device scaling, detailing its (7) role in shrinking transistor dimensions and reducing cost per transistor. Explain the key safety measures that must be followed by personnel in a (7) cleanroom environment to protect themselves and maintain contamination control. Include precautions related to clothing, handling of chemicals, equipment uses, and emergency procedures. State the importance of yield in semiconductor manufacturing. What is Lithography? Explain the Nanoimprint lithography. Describe the working principle of X-ray lithography and discuss its major advantages and challenges in modern semiconductor fabrication. What is PECVD technique and where is it used? (4)