Template for Qualification of the RAITH 150 EBL system.
James W. Conway
Updated November 24, 2004. Original March 12, 200 in RAITH Notebook No 2.
Purpose:
This document is intended to provide a step-by-step procedure to follow to perform
qualification testing on the RAITH 150 E-beam Exposure System. This qualification is
to insure that the system is operating properly and that the exposure results are within
factory specifications for the system before giving User’s access to the system.
Test and Checks To Be Performed:
Computers:
Hardware reset and boot functionality check
Disk File Clean up and Hard Drive Defragmentation routines.
Virus Scan with current virus definitions
Backup raith system and users file system to other Hard Drive storage
Backup copy of the RAITH150.vbd
RAITH and LEO Software Check:
Software functionality check
Errors encountered on Raith 150 app. Report all boot and HW module errors reported.
Hardware Checks:
Hardware reset – entire system power down and reset
Neslab Chiller inspection and functionality check
Water flow and N2 supply pressure check
Reset of ELPHY + pattern generator and beam blanking control unit
IEEE-488 and SCSI interface check
RS-232 / REMCOM check
Blanker functionality check
LEO SEM Platform:
Vibration Isolation System checkout
Mechanical Vibration isolation on SEM image check: Daily Image ripple image
Acoustic level of lab measurement. Measure sound level with acoustic meter.
Minimum SEM resolution achieved at 1 and 20 kV to specifications
Orthogonality calibration check
Beam spot stability check: beam drift spot mode 1 minute and 60 minutes.
Magnification amplifier calibration check at the junction of the three Mag. ranges.
Aperture(s) and Stigmation calibration, check of centering adjustments / function.
LEO Beam Blanker leakage test
SEM image capture and storage check. ABCC functionality check.
Stanford Nanofabrication Facility - Stanford University
For Internal Use Only
Template for Qualification of the RAITH 150 EBL system
RAITH Platform:
Image acquisition check
Magnification Calibration check on 'chessy' or NIST traceable Linewidth standard
Write field alignment functionality check
RAITH Beam Blanker leakage test
Find and establish ‘All Home Positions’ on Laser Stage & Interferometer calibration.
Stage kinetic mounts Piezo leveling controls calibration and functionality check.
FE-Gun:
Electron Beam emission stability
Emission level EHT ‘OFF’ versus EHT ‘ON’ evaluate FE-Gun settings.
Beam Current measurement at each aperture position
Beam Spot Drift to within specifications check. Spec = < 10 nm/minute.
Exposures:
A. Expose 2% 950K MW PMMA with 100 nm Thickness:
Baseline parameters:
10 kV, 30 um Aperture, 5 mm working distance at normal dose to clear:
Areas: 100 C/cm2 Single Pixel Lines: 330 C/cm Dots: 1ms dwell time.
Layer 1: Performance and Stitching Exposure
10 X 10 grid of origin_target.csf on 1000 m step U., V. to establish coordinate grid.
2 X 1 X 1000 m step U., V. DF 1.0, 1.1 of Demo.csf exposing layers 0-6, 8, and 10
2 X 1 X 1000 m step U., V. DF 1.0, 1.1 of Stitching (layer 0) in SOS.csf
2 X 1 X 1000 m step U., V. DF 1.0, 1.1 of GRATING_TEST.csf
4 X 2 X 0.200 m step U., V. DF 1.0, 1.1 of SPL10X10.csf
2 X 1 X 1000 m step U., V. DF 1.0, 1.1 of PCM1.csf
Save Position List and Layout view.
PLS # __________________________ DATE _________________________
Develop 1:
Develop: 1:3 MIBK:IPA 30 seconds with slight agitation @ 5 seconds.
Stop: Isopropanol 30 seconds
N2 Blow dry.
Microscope Inspection at 50 and 500 / 1000 X Magnification.
Layer 2: Overlay Exposure.
2 X 1 X 1000 m step U., V. DF 1.0, 1.1 of Demo.csf exposing layers 7,9,11, (12)
2 X 1 X 1000 m step U., V. DF 1.0, 1.1 of Overlay (layer 1) in SOS.csf
Stanford Nanofabrication Facility - Stanford University
For Internal Use Only
Template for Qualification of the RAITH 150 EBL system
Exposures: -- continued
Develop 2:
Develop: 1:3 MIBK:IPA 30 seconds with slight agitation @ 5 seconds.
Stop: Isopropanol 30 seconds
N2 Blow dry.
Microscope Inspection at 50 and 500 / 1000 X Magnification.
Evaluate for these Quality Factors:
- Resolution of smallest features written for Areas, Single Pixel Lines, and Dots.
-Write Field to Write Field Stitching evaluation
-Overlay registration evaluation
Exposure artifacts:
Blanking artifacts?
Scan Lines across structures written.
Unusual or aberrant features found on microscope and SEM inspection.
Exposure Proximity Effects
Total Commitment to Quality Issues:
Resist thin film quality after development: Pinholes, scratches, bubbles.
Pattern position accuracy and placement issues.
Sample Surface Charging issues affecting pattern placement or stitching.
Additional Quality Issues: To be determined.
Stanford Nanofabrication Facility - Stanford University
For Internal Use Only
Template for Qualification of the RAITH 150 EBL system
Data Collection & Measurement of the EBL Exposure result:
Inspection with optical microscope:
Microscope Inspection at 50, 500, 1000 X Magnification.
Area Dose to Clear determination
Write Field to Write Field Stitching
Pattern placement errors from sample surface charging effects.
SEM and Ebeam Scan Measurements:
Area Exposures:
Area Dose to Clear.
Minimum Line and space resolved
Minimum Gap resolved
Single Pixel Lines:
-Minimum feature resolved as measurement of the smallest CD Linewidth written
- Line Edge Roughness of a Single Pixel Line
-Grating Test and Resist Stripe Test
-Signal to Noise evaluation
Dots:
- Dot diameter, minimum feature obtained.
- Dot diameter for 1 ms shot dwell time
- Dot circularity on 500 nm pitch
Stitching and Overlay registration:
Simple test Write Field to Write Field
Raith stitching and overlay test using Ebeam line scan measurements.
Stanford Nanofabrication Facility - Stanford University
For Internal Use Only