Non-full depletion mode and its experimental realization of the lateral superjunction

Abstract

To realize the minimum specific on-resistance R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on, sp</sub> of the lateral superjunction (SJ) devices, the low resistance characteristic of the SJ should be adequately used and the adverse influence of substrate-assisted depletion (SAD) effect on the breakdown voltage V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B</sub> should be eliminated. From our previous equivalent substrate (ES) model, the SAD effect is completely suppressed if the ES is optimized. In this paper, the balanced symmetric SJ satisfying the optimized ES condition is defined as the ES-SJ. Based on the ES-SJ concept, the non-full depletion (NFD) mode of the lateral SJ is proposed and experimentally realized for the first time. In the experiments, the optimized ES is obtained by a linearly doped charge compensation layer (CCL) with a field plate covering the full drift region and the NFD SJ is implemented with a narrow width of 0.8 μm by implanting the SJ region thrice. The measured results exhibit a R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on, sp</sub> of 30.9 mΩ·cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> with a V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B</sub> of 477 V, which obtains a reduction in R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on, sp</sub> by 67.8% when compared with other SJ devices under the similar V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B</sub> .