High electron mobility single heterojunction semiconductor devices and methods of production of such devices.

摘要

A high electron mobility semiconductor device has a channel layer (7) and a source layer (8). For example, the source layer (8) contains a sufficient amount of n-type impurity to permit the accumulation of a quasi-two-dimensional electron gas (9) in proximity to a heterojunction (10) of the device formed between the layers (7 and 8). p-type impurity is selectively introduced into selected areas (12) of the source layer (8). In relation to those selected areas (12) the availability of electrons in the source layer is decreased, so that the quasi-two-dimensional gas cannot accumulate in proximity to regions of the heterojunction (10) corresponding to those areas (12). Thereby, the selected areas (12) function as isolation areas. In general, by controlling impurity concentration and/or impurity type in selected areas of the source layer (8) the appearance of the quasi-two-dimensional electron gas (9) can be inhibited or permitted selectively in correspondence with those areas.