Match the following : Codes :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
(a)-(iv), (b)-(iii), (c)-(i), (d)-(ii)
Three of the four links are unmistakable, and they fix the fourth by elimination.
(c) Hydrofluoric acid → (i) etching. HF is the one acid that attacks silicon dioxide, converting it to soluble fluosilicic acid while leaving the underlying silicon untouched. That selectivity makes it the standard wet etchant for opening windows in an oxide mask, and it is also why buffered HF is a laboratory staple in device fabrication.
(d) Float zone → (ii) crystal growth. The float-zone method grows a silicon boule by passing a molten zone along a polycrystalline rod held vertically, with no crucible touching the melt. Because the melt never contacts a container, oxygen and other impurities stay out and the resulting crystal is the purest available — which is why float-zone silicon is used for high-voltage power devices and detectors, while cheaper Czochralski silicon serves most ICs.
(a) Lift OFF → (iv) metallisation. Lift-off is the standard way of patterning metal that is hard to etch. A resist is patterned first, the metal is deposited over everything, and dissolving the resist carries away the unwanted metal, leaving the tracks behind. Its natural place in the process flow is the metallisation step.
(b) Rent's Rule → (iii) packaging. Rent's rule is the empirical relation between the number of external pins a block needs and the number of gates it contains:
\(T=t\,g^{p}\)
with the exponent p typically 0.5 to 0.7. Since it predicts pin count, it is a packaging and interconnect law rather than a fabrication one — it tells the designer how many pins a package must provide as circuits grow.
| Item | Belongs to | Code |
|---|---|---|
| Lift off | Metallisation | (iv) |
| Rent's rule | Packaging | (iii) |
| Hydrofluoric acid | Etching | (i) |
| Float zone | Crystal growth | (ii) |
The order (iv), (iii), (i), (ii) is option 2.
Hence, the correct match is (a)-(iv), (b)-(iii), (c)-(i), (d)-(ii).
Similar Questions
When silicon dioxide of thickness d is grown, the Silicon consumed is :
Match List - I with List - II.
List - I List - II (A) Annealing (I) Isolation (B) Sealing (II) Doping (C) Ion implantation (III) Packing density (D) Oxidation (IV) Crystal restoration Choose the correct answer from the options given below :
Arrange the following in ascending order based on their diffusivity :
(A) Boron
(B) Arsenic
(C) Antimony
(D) PhosphorusChoose the most appropriate answer from the options given below :
A thin layer of dopant is deposited onto silicon surface with a fixed total amount of dopants QT per unit area. If D is the diffusivity of dopants, then the surface concentration is :
The idea of using diffusion techniques was disclosed in patent by Pfann in the year :
Fick's second law of diffusion in one dimensional form can be expressed as :
The diffusivity determined experimentally over a range of diffusion temperatures can be expressed as :
For a diffused layer that forms a p-n junction an average sheet resistance RS is defined and related to junction depth xj, the carrier mobility μ, and impurity distribution C(x) as :
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 :
What is the name of adhesion promoter used in case of positive photo resist ?
Important Questions from Semiconductor Process Flow
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:
Arrange the given process steps in sequence for self-aligned gate formation.
A. Thermal oxidation to grow gate oxide.
B. Polysilicon deposition
C. Photolithography using gate mask
D. Etching of polysilicon and oxide
E. Source/drain diffusion
Choose the correct answer from the options given below:
- 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 :
