6 inch Wet Etch Hood

Wet chemical processes

Wafer cleaning is commonly the first step and may be used repeatedly throughout a process fabrication sequence. This may involve the use of acid and basic solutions, followed by a water rinse.

Cleans are designed to remove organic or metallic surface contamination as well as particulates. Furnace pre-cleans consist of a Piranha clean followed by silicon clean 1(SC1) and then silicon clean 2(SC2). Short etch steps are often done prior to metallization to ensure good contacts to semiconductors. Micro Electro-Mechanical Systems (MEMS) processes can utilize a long buffered oxide etches (BOE) for the release step.

Wet chemical etching is available with the following chemicals:     

1. Buffered oxide etch [BOE = ammonium flouride (NH4F) + hydrogen flouride (HF)] and HF solutions (such as 10 parts H2O + 1 part 49%HF).
2. Ammonium hydroxide (NH4OH) + deionized water (diH20).
3. Deionized water (diH2O) + nitric acid (HNO3) + phosphoric acid (H3PO4) + acetic acid (C2H4O2) - [Moly and aluminum (Al) etching).
4. diH20 + HNO3 + hydrochloric acid (HCl) - (ITO Etching).
5. PCT Megasonic clean (can be used with Detergent8 soap or without).
6. Each chemical tank has a QDR rinse tank associated with it.
7. Spin Rinse Dryer to dry the wafers after rinse.

Solvent Hood    

1. SRS Solvent Strip chemistry.

Equipment and hoods    

2. One acid hood.
3. One solvent hood.
4. Other chemistries can be used. Please check with FEDC staff.