Thomas Stiasny

The Corrugated P-Base IGCT - a New Benchmark for Large Area SQA Scaling

A 91 mm diameter IGCT with extraordinary safe operating area (SOA) is presented in this paper. The power density at turn-off reached values as high as 700 W/cm2, which is twice the previously reported SOA limit for devices with a comparable diameter. The improvement was achieved by masking one of the p-base diffusions, giving the p-base a corrugated appearance as well as improving the gate circuit.

The concept of Bi-mode Gate Commutated Thyristor-A new type of reverse conducting IGCT

In this paper, a new type of reverse conducting IGCT referred to as Bi-mode Gate Commutated Thyristor (BGCT) is discussed. The concept of the BGCT follows an interdigitated integration approach of an IGCT and Diode into a single structure while utilizing the same silicon volume in both GCT and Diode modes. This results in improved thermal behavior and current capability. The BGCT design concept differs from that of the conventional Reverse Conducting IGCT (RC-IGCT) since in the BGCT, each individual segment is designed either as a GCT cathode or Diode anode. With the aid of 2-D Sentaurus TCAD device simulations, we have compared the static and dynamic characteristics of a 91 mm 4.5 kV BGCT model in both GCT and diode modes with that of the equivalent RC-IGCT and asymmetric IGCT. Furthermore, we have also investigated the BGCT performance by varying the GCT to Diode segments ratio.

The 150 mm RC-IGCT: A device for the highest power requirements

A 4500V RC-IGCT switching more than 10 kA in both switch and diode mode was developed for application in cascaded multilevel topologies. The performance was facilitated by using most of a 150 mm silicon wafer for a single device. Furthermore, the stray inductance of the gate bushing inductance was lowered an order of magnitude, and the use of an outer ring gate contributed significantly to lower impedance on the device itself. Adjustment of the di/dt choke led to significant reduction of total losses. FCE as a means of loss optimization was investigated.

A Robust Reverse Blocking Switching Device for High Power Direct AC/AC and Current Source Converters

This paper deals with a reverse blocking semiconductor switching device, which is optimized for high power direct AC/AC and current source converters. It gives details on the main parts and design criteria in order to reach a robust device. In this paper, basic characteristics and test results are shown for a 400A, 6500V device and the high safe operating area (SOA) capability of the device is demonstrated.