:: IPCI ::

My Courses:

Techonolgy of microelectronic devices

Substrate preparation

Film deposition

Modifying the film properties

Etching
    Tutorials (2)
     Wet etching
     Dry etching

Fabricating devices

Wet etching tutorial

Modules

1. Theory of etching (wet, dry, etc..)
2. Wet etching

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HOW: Wafers are introduced in a liquid, as in the picture;the liquid reacts with film on the wafer, removing it, where it is not protected by resist

Disadvantages of wet etching:
- Not used for critical processes (structures < 2nm) - not good resolution
- Contamination of the wafer with particles from the liquid etchant
- Waste materials -the etchant is most of the time toxic for environment and there problems in disposing it after use
- Poor proces control (difficult to contol the etched thickness by measuring the etching time, due to various problems)
- Lack of anisotropy

Main three steps:

Movement of etchant to the surface
Chemical reaction
Movement of reaction products away from the wafer

Types:
- Immersion:
- Spray:

1. Theory of etching (wet, dry, etc..)
2. Wet etching

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