DRAM concept based on the hole gas transient effect in a AlGaN/GaN HEMT

In this paper, a concept for a 1T-DRAM in AlGaN/GaN based HEMTs is presented for the first time – the Hetero-RAM (HRAM). This memory takes advantage of the natural coexistence of both hole and electron gases and uses hole gas transient and dynamic capacitive coupling effects. It is interesting to note that up to now the hole gas has been considered as parasitic, since it was seen to trigger hysteresis and transient effects within the HEMT output characteristics. We discuss an implementation of the memory concept in a GaN/AlN/AlGaN HEMT structure with a Schottky gate, separated from the source and drain contacts via spacers which are used as storage nodes. The HRAM uses only one transistor and offers non-destructive read, relatively long retention time and fast programming while it is amenable to integration with conventional HEMT based technology.