Question

Lithography is:

• A. Top-down method used in preparation of nanostructure
• B. Bottom-up method used in preparation of nanostructure
• C. Top-down method used in preparation of bulk structure
• D. Bottom-up method used in preparation of bulk structure

Hint:

Think of "top-down" as a sculptor carving a statue from a block of stone. Think of "bottom-up" as building something with LEGO bricks. Lithography is like sculpting.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Nanofabrication techniques are generally categorized into two main approaches: top-down and bottom-up.


Top-down: This approach involves starting with a larger piece of material (a bulk structure) and carving, etching, or sculpting it down to the desired nanoscale pattern or structure.
Bottom-up: This approach involves building structures atom-by-atom or molecule-by-molecule through chemical synthesis or self-assembly.

Step 2: Detailed Explanation:
Lithography (such as photolithography or electron-beam lithography) is a classic example of a top-down method. The process typically starts with a bulk substrate (like a silicon wafer), which is coated with a light-sensitive material (a resist). A pattern is then transferred to the resist using light or an electron beam, and subsequent etching processes remove material from the substrate in the desired areas, creating a nanostructure.
Since it starts with a bulk material and selectively removes parts to create a smaller structure, it is a top-down method for preparing nanostructures.
Step 3: Final Answer:
Lithography is a top-down method used in the preparation of nanostructures.