A technique is presented which can significantly reduce the base-collector capacitance (Cbc) in AlGaAs/GaAs HBTs. Cbc is a key limiter of HBT microwave gain and bandwidth. The process uses high dose, high-energy ion implantation through the external base layer to compensate part of the heavily doped sub-collector. It also uses the more conventional self-aligned shallow implant to compensate the entire collector underneath the base contact. The total Cbc of the double implanted HBTs has been reduced more than 35% with this new technique as compared to devices with shallow implant only. Under proper conditions, the double implantation produces little damage to the base, thus the RF performance can be significantly improved. An fmax greater than 200 GHz has been obtained, comparable to the best previous reported results in common emitter HBTs.
|Number of pages||2|
|State||Published - 1 Dec 1995|
|Event||Proceedings of the 1995 53rd Annual Device Research Conference Digest - Charlottesville, VA, USA|
Duration: 19 Jun 1995 → 21 Jun 1995
|Conference||Proceedings of the 1995 53rd Annual Device Research Conference Digest|
|City||Charlottesville, VA, USA|
|Period||19/06/95 → 21/06/95|