| 摘要 |
A band-to-band tunnelling field effect transistor has been developed in the context of the invention. This transistor consists of doped source (38-40), doped drain (12a) and undoped channel (12) in a p-i-n structure. The channel is adjoined by a dielectric (13) which separates a gate (14, 19) for controlling the transistor from the channel. Between the undoped channel and the adjoining doped region, the tunnel junction is formed by a graded heterostructure (37, 40, 39) composed of at least a first material (A) (Ge) and a second material B (Si) having a larger band gap. Along the heterostructure, the concentration of material A firstly rises, assumes a maximum and then falls again. It has been recognized that only a very thin layer (40) with a maximum concentration of material A is required for such a structure, with the result that the critical layer thickness for defect-free monocrystalline growth does not have to be exceeded or has to be exceeded much less than in the graded (Si/Ge) heterostructure according to the prior art. |
