This article assesses the performance of a delta-doped In0.5Ga0.5P/GaAs heterostructure-emitter bipolar transistor (delta-HEBT) grown by low-pressure metalorganic chemical vapor deposition. Moreover, an HEBT without delta-doping design in the emitter and with spacer layers of various thicknesses is presented for comparison. The common-emitter current gain and offset voltage are 50 and 130 mV, respectively, for the HEBT without delta-doping layer. The offset voltage of the delta-doped HEBT is as low as 70 mV and its common-emitter current gain is increased to 55, because of the use of the optimum spacer thickness of 100 angstrom and the design of the delta-doped emitter layer. (c) 2006 Elsevier B.V. All rights reserved.