Low frequency noise in p+ -GaAs with non-alloyed contacts

Measurements of 1/f noise were performed including and excluding the influence of the contacts formed by metallic aluminum layers (MBE) deposited on the p+-type GaAs (MBE). The results show that the MBE process can produce non-alloyed ohmic contacts free of noise. The 1/f noise of bulk p+-GaAs is characterised by alatt≃5×10-

Complementary vertical bipolar transistor process using high-energy ion implantation

High-energy ion implantation is used as a key processing step in the formation of a complementary bipolar process with both transistor types being vertical. Both n-p-n and p -n-p transistors are made vertically with a deep implanted collector region. Combinations of epitaxial and buried layers are avoided. Both transistors have an ideal Gummel plot with a current gain of about 60. Cutoff frequencies of over 1 GHz have been measured, which is much higher than for conventional lateral p-n-p transistor

An 1 GHz all-implanted vertical pnp transistor

Vertical all implanted PNP transistors have been fabricated using high energy ion-implantation. The PNP transistor process can be implemented in standard NPN buried collector processes, with epitaxial layers larger than 2.5 μm, to achieve a high performance complementary bipolar process. The collector is formed by implantation of doubly charged boron ions with an energy of 500 keV. Base and emitter regions are also implanted. Independent change of the base concentration is possible. The base and collector currents are ideal over 5 decades. The current gain is ≅ 35 and constant over 4 decades. Cut off frequencies of the PNP transistors of over 1 GHz have been measured