HF Standard Operation Procedure

Updated on 10/16/2014

Warnings

• You must obtain training on the HF bench and get access to its calendar
• You must make a reservation before using the HF bench
• Before HF use, please refer to the emergency procedure [1] and MSDS [2].

Emergency Overview

• POISON! DANGER! CORROSIVE. EXTREMELY HAZARDOUS LIQUID AND VAPOR.
• CAUSES SEVERE BURNS WHICH MAY NOT BE IMMEDIATELY PAINFUL OR VISIBLE.
• MAY BE FATAL IF SWALLOWED OR INHALED.
• LIQUID AND VAPOR CAN BURN SKIN, EYES AND RESPIRATORY TRACT.
• CAUSES BONE DAMAGE.
• REACTION WITH CERTAIN METALS GENERATES FLAMMABLE AND POTENTIALLY EXPLOSIVE HYDROGEN GAS.

Note: Before you go into the area of HF wet bench, you must prepare the followings:

• Prepare wipes, Teflon sample holder and/or container for HF etch, and Teflon tweezers, because you are not allowed to go out of the area, wearing a face mask, an chemical resistant apron, and gloves, when you start the HF process.
• Do not use any glassware because HF dissolves glass.

• Identify the locations of HF first aid kit, eye washer, and shower.

• If you have an accident during HF process, then open HF First Aid Kit immediately. Follow the emergency procedure in the yellow envelope.

Operation procedure.

1. Fill out the wet bench log.

2. Inspect the following items: chemical resistant apron, face shield, and chemical resistant green nitrile gloves. Please notify staff is those items are NOT clean and dry.

3. In the following order put on: chemical resistant apron, face shield, and chemical resistant green nitrile gloves.
4. Turn on DI water to fill the rinsing bath.

• Note: Cover the DI water valve with a wipe to prevent HF contamination.

5. Set the sample onto the sample holder.

6. Immerse the holder with the sample into BOE (Buffered oxide etch, see ref. [3]) solution bath or HF solution prepared in Teflon container, to etch your sample.

7. Measure the etching time.

8. When the etching is done, rinse the sample in DI water bath.

9. Blow dry the sample on a wipe in the bench.

10. If you have mixed your own HF solution, please dispose of it into a waste bottle. (Waste bottles containing oxidizers are located on the bench; waste bottles that do not contain oxidizers are located in the HF storage cabinet). Please ask for staff help if you are not sure which waste bottle to use - do not guess!

• CAUTION! DO NOT THROW THE HF WASTE SOLUTION AWAY INTO THE SINK.

11. Wash Teflon container, sample holder, and tweezers in the DI water bath or the sink.

12. Wipe off any liquid on the bench, and throw the wipes away to a garbage for HF processing before the bench.

13. Wipe off any liquids off the apron, face shield, nitrile gloves.

14. Wash the nitrile gloves and dry them with wipers.

15. Turn off DI water.

16. In the following order take off: face shield, chemical resistant gloves, and apron.

17. Take the Teflon container, sample holder, and tweezers to the glassware storage.