A 1300V and a 1600V IGBT were realized by making use of n-/n+/p+ epitaxial layers and bulk silicon material respectively. Furthermore, the related key techniques for obtaining a high voltage IGBT were identified, which are the accurate design and optimization of the device longitudinal and lateral structure, and electrical parameters, the technological preparation of high quality thick Si layers wit low defect levels, and the formation of the composite junction-termination by both superposition and combination.