Application

SI WAFER SORTING

 

Sorter applications provide advanced multiparameter wafer inspection with integrated high speed sorting for quality control of production PV wafers. Owing to wide range automation module portfolio and flexible combined Semilab’s metrology modules, all customer can find perfect configuration what fulfil their production expectations.

Application area:

  • Outgoing wafer inspection for wafer manufacturers
  • Incoming as-cut wafer inspection for solar cell manufacturers

Sorter purpose

  • Eliminating damaged wafers from further process
  • Eliminating high thickness variation wafers (TTV, saw mark)
  • Sorting of potentially weak wafers (microcracks) which could break in subsequent process steps
  • Sorting based on resistivity, and lifetime values
  • Sorting of wafers with dislocations, high contamination and vacancy density
  • Wafer input: loading from cassettes or stack
  • Wafer output: Sorting in different user-defined classes, collection in coin stacks
  • High throughput

 

Technology

GEOMETRY INSPECTION
MICROCRACK INSPECTION
PHOTOLUMINESCENCE IMAGING
SAW MARK INSPECTION
SURFACE-CONTAMINATION AND CHIPPING INSPECTION
THICKNESS AND RESISTIVITY MEASUREMENT
µ-PCD CARRIER LIFETIME FOR WAFERS

PHOTOLUMINESCENCE IMAGING

 

Photoluminescent Imaging is an excellent tool for monitoring of multicrystalline, monocast or monocrystalline wafers. During the measurement, the laser illuminates the silicon block and the generated photoluminescent signal is detected by an IR camera. The illumination effects the recombination of charge carriers. If not, the defects are present and there is a chance of radiative recombination. During the radiative recombination, a photon is emitted which can be detected by an IR camera. PL intensity is inversely proportional to defect density and impurity concentration.

System features:

  • High quality fast imaging even for as cut wafers
  • Advanced on-the-fly lifetime calibration method 
  • Flexible classification according to the particular requirements
  • Detection of wafers with broken edge
  • Capability to measure solar wafers at any processing stage providing full process control
  • Accurate tool matching capability
  • Cell efficiency forecast capability at as-cut stage
  • Flexible configurability from stand-alone to integration in fully automated systems

TYPES OF DETECTABLE DEFECTS:

1. Material (as-cut wafers):

General

  • High contamination density
  • Edge (corner) contaminations

Multi wafers

  • High dislocation density
  • Active grain boundaries

Mono wafers

  • Ring defects (for different reasons)
  • Pinholes
  • Cracks

2. Passivation control (double side passivated samples)

Optional on-the-fly Jo and iVoc mapping

3. Wiring (finished cells):

Shunt

Edge isolation defect

Bad finger


PL IMAGES AT DIFFERENT PROCESSING STAGES:

 

COMPARISON OF PLI AND LIFETIME FEATURES:

Good correlation between PL and μ-PCD data allows calibration between PL intensity and lifetime:

              PL image

            μ-PCD image

 

Point-to-point correlation of Multicrystalline wafers with lifetime:

 

                PL image

              μ-PCD image

 

CORRELATION BETWEEN FORECASTED AND MEASURED CELL EFFICIENCY


Semilab’s sorting solution provides good consistency between multicrystalline wafers and efficiency of final cells.

 


COMPARISON OF J0 AND IMPLIED VOC MAPPING BY QSS µ-PCD

 

 

FEATURES

  • Reflection side photoluminescence on finished cells, processed and as-cut wafers
  • On the fly lifetime map from µ-PCD calibrated PL image
  • Applicable for R&D usage
  • Quality description by calibrated lifetime map and customizable classification parameters
  • Cell efficiency forecast from PL images as-cut multi/monocast wafers (calibration required)
  • Measurement capability both on slurry and diamond-cut wafers

Product Line

PVS

Photoluminescence tool for wafer and cell inspection is a fast and reliable solution for non-destructive measurement of wafer and cell quality at any stage of processing from as-cut wafers to finished cells.
Provides full control of material quality during the whole production.
Higher quality wafers create higher efficiency cells making the production more cost-efficient.

Products

PVS-5000

PVS-5000

PVS-5000 is a high throughput, field proven PV Wafer Inspection and Sorting System.

It combines high reliability wafer handling with Semilab’s industry leading PV metrology, to provide a turnkey solution for sorting of incoming wafers. This is backed by direct expert support from the OEM metrology manufacturer, through our worldwide network of branch offices.

Loaders

  • PVLS-5400          Automated stack loader with 3 position pick-and-place system. Up to 2400 pcs buffered wafer in 12 pcs carrier.
  • PVLC-3600*       Automated cassette loaders for 25/50/100 slot cassettes
  • PVLC-3600-AL   Fully automated production line loader for 100 slot cassettes

Metrologies

Unloaders

  • PVULS-5406T     High speed stack unloader with 6 bin
  • PVULS-5407T     High speed multilevel stack unloader with 7 bin

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PVS-6000

PVS-6000

PVS-6000 is a High Speed, field proven PV Wafer Inspection and Sorting System with 5400 wafer per hour throughput. It combines high reliability wafer handling with Semilab’s industry leading PV metrology, to provide a turnkey solution for sorting of incoming wafers. This is backed by direct expert support from the OEM metrology manufacturer, through our worldwide network of branch offices.

Loaders:

  • PVLS-5400        Automated stack loader with 3 position pick-and-place system. Up to 2400 pcs buffered wafer in 12 pcs carrier.
  • PVLC-3600       Automated cassette loaders for 25/50/100 slot cassettes
  • PVLC-3600-AL   Fully automated production line loader for 100 slot cassettes

Metrologies:

Unloaders:

  • PVULS-5406T   High speed stack unloader with 6 bin
  • PVULS-5407T   High speed multilevel stack unloader with 7 bin

Request Info