Field effect transistors with hydrogenated diamond

Diamond is expected to be the most suitable material for high speed high power electronic devices because of the high breakdown field, high carrier mobility and high thermal conductivity. Due to the missing of a technically relevant n-type doping, diamond is limited to unipolar devices like the field effect transistor (FET). Two ways exist to achieve p-type conduction in diamond, namely the incorporation of boron into the diamond crystal [1] and the termination of the surface with hydrogen [2]. Field effect transistors can be fabricated with both options, each with its own challenges. A combination of boron doping with hydrogen termination for MESFET/MISFET structures is possible as well [3]. Fig. 1 shows a DC output characteristic measured with a FET on hydrogenated diamond.

The details investigated in this work are:

  • FET-Layout
  • Physical simulation of FET structures
  • Fabrication technology
  • DC and RF characterization of fabricated FETs

Fig. 1. DC output characteristic of a FET on H-terminated diamond with a gate length of LG=1 µm.

M. Kunze, A. Vescan, G. Dollinger, A. Bergmaier, E. Kohn; delta-Doping in diamond, Carbon 37 (1999), 787.
H. Kawarada; Hydrogen-terminated diamond surfaces and interfaces, Surface Science Reports 26 (1996), 205.
D. Kueck, H. El-Hajj, A. Kaiser, E. Kohn; Surface-channel MESFET with boron doped contact layer, Diamond & Related Materials , to be published.