A new HCBT with a partially etched collector

A novel horizontal current bipolar transistor (HCBT), suitable for the integration with the pillar-like MOSFETs, is processed with the reduced volume of the parasitic regions, achieved by the partial etching of the collector n-hill region and the self-protection of the p/sup +/ extrinsic base from tetramethyl ammonium hydroxide etch-back. The HCBT fabricated by a low-cost technology exhibits the cutoff frequency (f/sub T/) of 30.4 GHz, the maximum frequency of oscillations (f/sub max/) of 35GHz and the collector-emitter breakdown voltage (BV/sub CEO/) of 4.2 V, which are the highest f/sub T/ and the highest f/sub T/BV/sub CEO/ product among the lateral bipolar transistors (LBTs).