Reliability Methods and Standards for WBG Device Production Testing

July 19, 2018 by Paul Shepard

Reedholm Systems announces, effective immediately, that the Company has formally engaged with The Piner Research Group (located on the Texas State University Campus) to develop reliability methods and standards for production test of WBG devices (wide band gap) as well as to provide technical consulting services to Reedholm Systems.

The parties recognize the unique needs and challenges faced by WBG device manufacturers and Reedholm Systems‘ need to refine its measurement instrumentation and long-term reliability stress capabilities specifically for the GaN, SiC, GaN on Si, and other WBG devices & materials.

The terms of the Agreement with The Piner Research Group also call for Reedholm Systems to install one of its industry leading 10kV/50A WBG Parametric Test Systems for process control and die sort measurements of WBG devices.

Reedholm has configured an integrated system, not just a set of boxes, for testing high power devices at the wafer level. Sophisticated testing, prober control, and database management do not carry a programming burden. As a result, fast, automated wafer testing is done in an inexpensive, compact probing platform.

A simple, rugged rectangular probe card interface eliminates the bulky and complicated test head that makes other testers expensive and difficult to maintain. The interface is compatible with high pressure probing that uses the Paschen relationship to reach high breakdown voltages without having to use Fluorinert.

Because the tester is based on a modern parametric tester, precise device measurements are possible, not just pass/fail or binning measurements. Crosspoint matrix connections increase the type and quality of measurements beyond what is feasible with three or four dedicated connections to cover:

  • Bipolar, JFET, &MOSFET characteristics.
  • High frequency (100kHz) capacitance.
  • "Zero current" Rdson measurement.

The system can also be extended for reliability stress test requirements for HTOL, HTRB, and HTGB requirements (depicted below) for WBG research projects undertaken by Reedholm Systems personnel, the Piner Research Group and Texas State University PhD students.