MiPLATO-SiC SiC Wafer Defect Inspection System

SiC Wafer Defect Inspection System

The SiC Wafer Defect Inspection System MiPLATO-SiC is a PL mapping system optimized for SiC wafers.
It acquires the spectrum of the entire wafer in a short time using spiral mapping, enabling simultaneous measurement of defect density, carrier lifetime, and film thickness variation. The deep-learning function performs automatic defect classification, enabling advanced defect type identification and assessment. The Auto Navigation function during spectrum mapping allows defect location identification and automatic tracking using PL map coordinates, DIC images, stage coordinates, etc. This system is capable of detecting and analyzing fine defects on wafers.

Segment: Semiconductor

Division: Metrology

Features
Specifications

General Features

• Simultaneous measurement of 3-channel photoluminescence and 1-channel DIC laser microscopy using a 355nm laser source
• Deep learning for defect analysis
• DIC Laser Microscopy Surface Inspection
– Reflected DIC laser microscope of excitation source (355nm)
– Carrot, Scratch, Droplets, 3-C triangular defects
• Band edge PL inspection method, additional 2 types of data for user reference
– BPD, Shockley stacking faults, Bar type stacking faults
• Photoluminescence spectral mapping with spectrometer
– Whole wafer mapping
– Spectroscopic analysis for aimed area in map data
• Auto-Navigation Function
– Auto-defect inspection using spectral measurement using PMT mapping and image processing result
– Exact stacking faults classification by spectrum analysis

Optical Configuration

• Spiral scan with 1800 RPM (Max) rotation stage
– One head type & Two head type (under development)
• Micro PL with 50x objective lens
– 2um beam size
• Multi detectors :
– Default : reflected DIC, Band – edge PL, Spectrometer
Two additional customer designed PL defectors

Spectrum mapping (Macro)

• Macro mapping for substrate & Epi-wafer can be used for QC
– Growth machine to machine
– Ingot to ingot
– Wafer to wafer in ingot
– Wafer uniformity
> 5 mins/ 6” with 3mm step

Spectrum mapping (Micro)

Auto-Navigation function

• screen capture image of spectrum acquisition process
1. Mapping Image by PMT
2. Cropped Imgae of SF being measured
3. Spectrum ddata of SF
4. Detailed information of SF from spectrum
5. Report of Classified SFs

Mapping Result

General Specification.

Scan method		Spiral scan with 1800 RPM rotation and linear motion
Laser		20mW 355nm CW Laser * Beam size on surface : 2um diameter thru 50x objective lens
Detector		4 PMTs, 1 Spectrometer
Stage		XY-axis Linear stage R stage with 1800RPM (Max)
Measurement	PMT1	DIC 355 Laser line for surface inspection
	PMT 2,3,4	PL Port 2 (PMT 2) : PL Inspection with 390nm bandpass filter PL Port 3 (PMT 3) : 420 nm ~ 500 nm default. But customer choose bandpass filter between these range PL Port 4 (PMT 4) : 3C triangular defects with 540 nm bandpass
	CCD camera	Image of designated position in analysis process
	Spectrometer	Spectrum between 380 nm ~ 700 nm Detailed defects analysis, Macroscopic wafer deep level mapping
Measurement speed			4inch	6inch
		PMT Mapping (4 channel at same time, 5um step)	8pcs / 1H	6pcs / 1H
			16pcs / 2H	12 pcs / 2H
		Spectrometer mapping 3mm step		5 min
Dimension (mm)		2000 (w) x 1400 (d) x 2000 (h)

Utility.

Operating Environment	Place	Clean Room (class ~ 10000)
	Temperature	15 ~ 35° C
	Humidity	< 85 % RH with no condensation
Utility	Dimensions	1500 mm x 2000 mm x 2300 mm, incl. HEPA filter
	Weight	1760 kg
	Input Voltage	220V± 10% 50 / 60Hz single phase
	Full load current	47A
	Vacuum1	40L / min, -80KPa Pipe size : Outer diameter 6mm
	Vacuum2	120L / min, -40KPa Pipe size : Outer diameter 6mm
	Air	90L / min, 0.5MPa Pipe size : Outer diameter 6mm

MiPLATO-SiC