MDPinline

One wafer a second! Production integrated high speed wafer mapping of carrier lifetime. Single wafer topograms in less than one second a wafer.

Inline full wafer mapping at one wafer a second

MDPinline is a compact high speed production integrated mapping tool for quantitative measurements of carrier lifetime. Topograms are measured ‘on the fly’ in less than one second a wafer while the wafers are moved underneath the instrument by the conveyor as installed in the factory.

The instrument itself uses no mechanically moving parts making it extremely reliable also under continuous operation. The availability of a full topogram for each individual wafer offers new ways to increase the cost effectiveness and efficiency of production lines which were so far completely out of scope. For example, an automated statistical evaluation of 10.000 wafer topograms, which are obtained within less than three hours, reveal surprisingly fine details of the performance of crystal growth furnaces as well as material quality.

Si3N4 and SiC segregates in multi-crystalline silicon
Microcrystalline inclusions
Investigation of passivation quality...
Cz-Si with bulk defects, separation...

Processing steps such as diffusion and passivation may be ramped up and optimized within so far impossible timescales at highest performance, due to real time quality and homogeneity investigation. In the running production, any failure of a processing step may be detected immediately. On the other hand, if wafers are sold to a customer, higher prices are achieved, if each wafer exhibits a guaranteed performance leading to a return of investment for the MDPinline within less than a year.

Facts

  • contactless destruction free electrical semiconductor characterisation

  • production integrated high speed wafer mapping, suitable for statistical process control (SPC)

  • allows to identify cell efficiency limiting material and processes at early production stages

  • suitable for single wafer investigation

  • complete two dimensional wafer map, in less than one second

  • mapping capability of: carrier lifetime, line scan of resistivity

  • advanced sensitivity for visualisation of so far invisible defects also in processed wafers

  • easy to integrate, statistical data output and quality class definition

Advantages

  • Full electrical wafer characterisation at speeds up to one wafer in less than a second. Measured parameters: Carrier lifetime (full topogram), resistivity (two line scans).

  • So far not seen efficiency of process control, yield and process improvement allow for an extremely fast upramping of new fabs or processes, since statistical information from thousands of wafers are obtained in a very short period of time.

  • Suitable for measurement of material quality of outgoing or incoming wafers as well as identification of crystallisation problems at wafer level for instance in PV industry. Well suited for diffusion process integrity control, passivation efficiency and homogeneity control.

Multicrystalline silicon wafers

Technical specifications

sample thickness100 μm up to 1 mm
sample sizebetween 125 x 125 to 210 x 210 mm² or 4” up to 18”
resistivity0.2 - 10³ Ohm cm
conduction typep, n
materialsilicon wafer, partially or fully processed wafers, compound semiconductors and beyond
properties measureableminority carrier lifetime (steady state or non equilibrium (μ-PCD) selectable)
measurement spot2.8 mm default, others possible
measurement timeless than 1 second for each full wafer map
dimension400 x 400 x 450 mm, weight: 29 kg
power24 V DC, 4 A

Detail

  • allows for single wafer control

  • parameter auto setting, predefined sorting recipes

  • up to 15 quality classes automated wafer sorting

  • monitoring of material quality, process integrity and stability

  • fast up ramping of processes and production lines