Aurora TCM-120i/TCM-121i

Inline Non-Contact Bi-facial Transparent Conductive Oxide Measurement

The TCM-120i/TCM-121i system accurately and reliably performs simultaneous measurement of front and rear transparent conductive oxide (TCO) layers on silicon substrates. This unique system operates inline at full production speeds. The sensor uses safe infrared light to produce high-resolution characterization of TCO sheet resistance and thickness from edge-to-edge on a wafer.

DM-121 Measurement Pattern
DM-121 Measurement Pattern


The DM-121 system measures the front and rear TCO sheet resistances and thicknesses on silicon photovoltaic (PV) wafers. This innovative product provides the industry’s only means to measure these properties in heterojunction technology (HJT) cell production lines. Both sheet resistance and thickness are measured at a series of discrete points along the centerline of each wafer. The DM-121’s patented technology provides accurate real-time measurements for process control and optimization.

The system consists of a specialized pair of DM-100 series measurement heads, designed as a unit to fit above and below a wafer conveyor, and measures 100 percent of wafers at full production line speeds. The system can connect to Aurora’s Visualize™ quality control system for integration of measurements with process tools to provide real-time 3D visualization of intra-tool dynamics, both spatially and by batch. This enables optimization of PVD or RPD processes.



  • Non-contacting continuous TCO sheet resistance and thickness measurement
  • Both front and rear layers measured simultaneously
  • Designed for 100% wafer measurement up to 5000 wafers/hour
  • Rock-solid long term measurement stability
  • Encoder controlled measurement triggering
  • Highly accurate and repeatable
  • Compact and easily installed



  • Allows true characterization of both short and long term process behavior
  • Eliminates operator error and inconsistencies in offline measurement
  • Minimizes wafer damage caused by handling and four-point probe contact measurement
  • Reduces labor costs associated with offline sampling and SPC charting
  • Rapid payback



Measurement Range (thickness)
20 - 200 nm
Measurement Resolution
1 x 10 mm circle
Wafer Throughput
Up to 5000 wafers/hour
Transport Speed
Up to 850 mm/s
Standoff From Wafer (top side)
5 mm
Standoff From Wafer (bottom side)
5 mm
Minimum Wafer Size
125 mm
Operating Temperature
20 to 25 °C
6 kg
191.5 mm x 132 mm x 200 mm
6 x M5 (per measuring head)
Ventilation Clearance
100 mm (top and bottom)
Power Interface
24 VDC (Provided by DM-Hub)
Remote Maintenance Interface