Estimation of future demand for neutron-transmutation-doped silicon caused by development of hybrid electric vehicle and its supply from research reactors

The neutron transmutation doping technology (NTD) is introduced to the semiconductor society, and the feasible future demand for the NTD wafers is presented in order to support the appropriateness of the construction of the NTD-dedicated neutron source. It is confirmed that neutron-transmutation-doped floating-zone silicon wafers are very useful in IGBTs which control the electric traction motors equipped in hybrid or electric vehicles since NTD-Si has the best quality among all the doping methods. Thus, it was estimated that the hybrid electric vehicle industry would be the main end user for NTD wafers in the future. The required quantity of the NTD silicon in a hybrid electric vehicle was estimated, and the prospect for the production of the HEV was surveyed. Then, the worldwide demand for the NTD silicon associated with the HEV production was deduced. It was confirmed that almost 1000 tons of NTD silicon will be needed in 2030 to meet the demands of HEV production. At present, the worldwide capacity of the NTD facility was estimated to be 150~180 tons per annum. Therefore, inevitably, the doping facility with a large irradiation capacity for NTD such as a reactor dedicated to silicon irradiation should be constructed. This work can be utilized as the basic material for the construction of a new doping facility.