Study on vertical structure of a gate commutated thyristor

Based on the theoretical analysis of factors which limit the voltage blocking capability of a gate commutated thyristor, simple design criteria are developed to calculate the thickness of the N base. Compared with a conventional gate turn-off thyristor design, silicon thickness can be cut by 1/3. Device parameters are optimized by two-dimensional simulation. Isolation groove between the cathode and gate is formed by wet etching. Experimental results obtained show that the ratio of the width to depth of the groove is approximately 0. 8 when the depth of the groove is larger than 20 micra, and the etching rate becomes slow because the etch byproducts limit the mass transport of the etchant to the silicon etch surface.