RCA Cleaning Hood

2024-12-20 to 2025-01-02: Reduced Holiday Operations

Dear Birck Research Community,

The Purdue winter recess begins effective Friday afternoon December 20th and concludes Thursday morning, January 2. The university is officially closed during this time. As we have done in past years, the Birck Nanotechnology Center will remain available for research but will be unstaffed and hazardous gasses will be unavailable. Lab work may otherwise proceed, though any fume hood work must be done with someone else present in the same laboratory or cleanroom bay (the "buddy" system). Click the link above to get more detail about equipment conditions and rules.


Refer to the Material and Process Compatibility page for information on materials compatible with this tool.
Equipment Status
: Set as UP, PROBLEM, or DOWN, and report the issue date (MM/DD) and a brief description. Italicized fields will be filled in by BNC Staff in response to issues. See Problem Reporting Guide for more info.

StatusUP
Issue Date and Description


Estimated Fix Date and Comment


Responding Staff

DO NOT USE III-V or LiNbO3 SUBSTRATE MATERIALS IN THIS HOOD!


DO NOT USE METAL OR COATED METAL TOOLS IN OR NEAR THIS HOOD



iLab Name: RCA Hood & Spin Rinse Dryer
iLab Kiosk: BRK Utility Core
FIC: Shared
Owner: Rich Hosler
Location:
Cleanroom - R Bay
Maximum Wafer Size: 4
"/100 mm

Overview

See Also: Cleaning

General Description

The RCA cleaning process was developed to remove organic contaminants, oxide layers, and ionic contamination from silicon wafers prior to subsequent processing steps. This hood and spin rinse dryer combination allows for the procedure to be performed much more quickly and effectively than inside a standard hood. The hood is a Kinetics Celera ventilated polypropylene wet bench with a quick dump rinse tank, two heated baths, one standard bath, digital controls for drainage and heating, nitrogen gun, and UPW water gun. The Semitool Spin Rinse Dryer is designed to rinse a cassette of 4" wafers with UPW water until clean, followed by a spin dry process. 

RCA Cleaning Procedure

SC1 – Organic and Particle Clean

A mixture of UPW, NH4OH (Ammonium Hydroxide 29%), and H2O2 (Hydrogen Peroxide 30%) at approximately 80°C removes organic residues and particles.

HF – Oxide Strip

A mixture of HF (Hydrofluoric Acid 49%) and UPW at ambient temperature removes thin oxide layers and some ionic contaminants.

SC2 – Ionic Clean

A mixture of UPW, HCl (Hydrochloric Acid 37%), and H2O2 (Hydrogen Peroxide 30%) at approximately 80°C removes remaining metallic (ionic) contaminants and leaves a thin passivizing layer on the surface.

Equipment Specifications

  • SC1 & SC2 Baths
    • Bath temperature - maximum of 85°C, thermally alarmed. 
    • Drain controller with temperature lockout - system will not drain above 45°C.
  • HF Dip Bath
    • Manual drain control
  • Quick Dump Rinse
    • Above & Below rinse/fill controller with automated dump and fill cycle control
  • Dedicated chemical storage cabinet and peroxide fridge.
  • Dedicated PPE station
  • Spin Rinse Dryer - Resistivity controlled UPW rinse controller, 300-1800RPM rotational speed.

Sample Requirements and Preparation

  • DO NOT USE III-V SUBSTRATE MATERIALS IN THIS HOOD!
  • Max Wafer Size: 4"/100 mm for cassette cleaning and spin drying
  • 5-part 1x1cm piece holder

Standard Operating Procedure

Effective 12/5/2019

Questions & Troubleshooting

RCA Cleaning Hood and Spin Rinse Dryer SOP:

RCA Cleaning Protocol V4.pdf

Problem: The bath heater won’t start.

  • Solution 1: The bath level may be too low to begin. Ensure you have added enough liquid and clear the alarm reset panel.
  • Solution 2: The drain control is open. Close it via the control panel.
  • Solution 3: The heater limit has tripped due to a previous overtemperature. Press the ‘bath limit reset’ button and clear the alarms from the control panel.


Process Library

Process Type

Step 1

Step 2

Step 3

Step 4

Pre-Oxidation

Piranha

HF Dip

SC1

SC2

Pre-Anneal

SC1

SC2



Pre-Contact

SC1

HF Dip



Post-Strip

Piranha

SC1



Post-Etch

HF Dip

Piranha

SC1


Post-CMP

HF Dip

SC1