High-speed 6.1 Angstrom InAs HBT devices and circuits

The paper presents high-speed 6.1 Angstrom InAs HBT devices and circuits highlighting areas where HBT compare favorably to other devices as well as pointing out areas where technology requires additional development. The major differences between InAs technology and other HBT technologies is the lack of suitable lattice-matched semi-insulating substrate for InAs. The circuit consist of 62 transistor, sub-collector resistors and two layers of metal interconnect. A key parameter for determining the speed of an HBT is the base resistance. A base sheet resistance of 490 /spl Omega//sq was measured from a 400/spl Aring/ thick InAS layer doped p-type with Be at 1.5/spl times/10/sup 19/ cm/sup -3/ and good gain is achieved at this doping level.