A. For impurity diffusion in semiconductor, concentration gradient is the only essential requirement. B. Annealing is a mandatory step after ion-implantation. C. Wet etching is normally anisotropic D. High temperature is required for the growth of $SiO_2$ because oxidation reaction takes place at high temperature E. Bird's beak formation is a characteristic of LOCOS isolation Choose the correct answer from the options given below:
Semiconductor Fabrication Concepts Analysis
Evaluating each statement regarding semiconductor processing:
- Statement A: Impurity diffusion relies on a concentration gradient, but other factors like temperature are also essential. Thus, A is incorrect.
- Statement B: Annealing post-ion implantation is mandatory to repair lattice damage and activate dopants. Thus, B is correct.
- Statement C: Wet etching is generally isotropic, unlike anisotropic dry etching. Thus, C is incorrect.
- Statement D: High temperatures are necessary for $SiO_2$ growth kinetics. The statement's explanation is circular. Thus, D is incorrect.
- Statement E: Bird's beak formation is characteristic of the LOCOS isolation process. Thus, E is correct.
Final Answer Selection
Statements B and E are correct. This corresponds to Option 3.
Important Questions from Semiconductor Process Flow
- Match the LIST-I with LIST-IIChoose the correct answer from the options given below:
LIST-I LIST-II A. Shallow trench isolation (STI) I. Low static power dissipation B. Junction isolation II. High static power dissipation C. CMOS technology III. High component density D. Bipolar IC technology IV. Low component density Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R
Assertion A: Impurity diffusion in semiconductor essentially needs very high temperature.
Reason R: Diffusivity of impurity atoms is negligibly small at room temperature.
In the light of the above statements, choose the most appropriate answer from the options given below
- In particle beam lithography, the resolution depends upon :
Match the following :
List - I List - II (a) Lift - off (i) Fick's Equation (b) Dry Etching (ii) PMMA (Poly Methyl Methacrylate) (c) Lithography (iii) Bombardment of Plasma (d) Diffusion (iv) Structures of Target Material on the Surface of Substrate Codes :
Match the following :
List - I List - II (a) Lift OFF (i) Etching (b) Rant's Rule (ii) Crystal Growtd (c) Hydrofluoric acid (iii) Packaging (d) Float zone (iv) Metallisation Codes :
