The Advantages of NTD Silicon for High Power Semiconductor Devices

Abstract

The float zone silicon used in manufacturing high power semiconductor devices is known to have resistivity variations. These variations are large enough to create an unwanted distribution around given design values such as blocking voltage, turn-on characteristics, on-state voltage drop, reverse recovery, and turn-off time. Both domestic and foreign vendors now supply NTD (neutron transmutation doped) silicon. The significant advantage of this process of manufacturing n-type silicon is it provides a narrow resistivity range and low radial resistivity gradient. A more desirable distribution of electrical characteristics and a higher blocking voltage distribution results in devices made using NTD silicon. The advantages of NTD silicon on these device parameters will be discussed in detail.