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.

Status	DOWN
Issue Date and Description	10/30/24 Water leak inside chamber due to hearth damage as a result of unscheduled cooling water disconnect and a failure of the water flow interlock.
Fixed Date and Comments	Damage assessment underway.
	Dave Lubelski/Dan Witter

Lesker Kiosk Home Page

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iLab Name	C - Lesker E-Beam Evaporator - Flexible Substrate Compatible
iLab Kiosk	BRK Evaporation Sputtering Core
FIC	Shared
Owner	Dave Lubelski
Location	Cleanroom - K Bay
Max. Wafer	6"/150 mm

Current Sources	Ti, Cr, Au, Ag, Pt, Al
Potential Sources	Ti, Au, Cr, Pt, Al, Ni, Mo, Pd, Ag, ITO, Al2O3, Ta2O5, SiO₂

Overview

General Description

Six Pocket E-Beam Evaporator
Water-cooled, rotatable stage
Used for approved flexible substrates
Quick pumpdown to 5x10^-7 torr
Handles up to 6" substrate

Specifications

Source Materials: Ti, Au, Cr, Pt, Al, Ni, Mo, Pd, ITO, SiO2
Deposition rates range from .2^-10 Angstroms/sec
System Pressures of 5x10^-7 torr
Primarily used for deposition using flexible substrates

Sample Requirements and Preparation

Make sure your sample has been properly baked when using any PR or PMMA OR POLYIMIDES.

Substrates must be solvent cleaned in the standard 3 step Toluene, Acetone, and IPA solvent clean.

Samples must be cleaned in accordance to processing needs only Flexible substrates approved by Staff are allowed in this Tool.

Maximum Thickness oxide source is 300 nanometers if you need to do more than 300nm it must be done during business hours Mon-Fri 7-5 so staff can check the source

Spin on Polyimide sample for metal deposition must be prepared in cleanroom.

Thickness: < 13um
Soft bake above 120 C longer than 30 seconds.
Curing in cleanroom /wiki/spaces/BNCWiki/pages/6228522 at:
- 1) 200C for a minimum of 30 minutes
  Followed by:
- 2) A minimum of 300 C for a minimum of 60 minutes
Gradual cooling to room temperature (cooling overnight)

Standard Operating Procedure (Link)

Please Note: This instrument is billed per use based on a 4 hour block

Example : 1 user only uses the tool per use. When you vent the system and unload your sample that concludes your reservation .

Example: If the usage is 10+ minutes past the initial 4 hour reservation, you will be billed for 2 uses

Questions & Troubleshooting

I had a problem with the way the last aluminum samples turned out. It looked like there were almost pin holes or something in the aluminum layer. I am not sure if you know what may have been wrong but I can show you the samples and maybe you have an idea of what caused it.

The pinholes are most likely caused by contaminates on the substrate , below are some more comments

Dr A. Kumar

Harcourt Butler Technological Institute

Dear Dr. Sivagami

Deposit the film at higher vacuum than what you are using at present. For good adhesion, Degass the substrates before deposition. Make slightly thicker films. Anneal them after evaporation in vacuum at higher temperatures for getting rid of voids. See if you are able to solve the problem. Substrate cleaning can also be improved for better uniformity. Good luck.

Dr A. Kumar

Harcourt Butler Technological Institute

If substrates are glass plates, degassing is done by putting a heater inside the coating unit over the substrates and heat them up to 200 degree centigrade for about two hours in vacuum. The gasses absorbed comes out in this process. Switch off the heater to cool down to room temperature. Thereafter, deposit the film without exposing them to air.

Pradip Kumar Dey

Added an answer

pinholes are mainly created due to any foreign material already present in the substrate and they tries to come out through the deposited films during deposition. Clean your substrate thoroughly in piranha solution (1:1 ratio of H2O2 and H2SO4 for 20 min. ** you can search in net for details) . Thereafter rinse in DI water and preheat in oven @ 150 deg. Cent. for at least 30 min and then place in thermal chamber for deposition. Also you should heat your substrate up to 150 deg. cent. just before deposition. For better film quality high vacuum is essenti

Reed Schmell

Independent Researcher

Pinholes are either caused by surface contamination remaining on the "cleaned" surface. Use the water break test to determine if the surface is residue free. You will see interference fringes as it dries. The fringes will be even as the water evaporates. Any island fringes or streaks means the surface is not clean. Any of these particles actually become nucleation sites as the coating is deposited

Process Library

References

Lesker E-Beam Evaporator - Flexible Substrate Compatible