Ion Beam Centre

Electronic materials

Ion Beams can be used to modify the electronic and optical properties of electronic materials such as semiconductors and superconductors.

The Ion Beam Centre regularly undertakes research work in the following areas of ion beam modification of electronic materials:

  • Group IV Semiconductors
  • Optoelectronics
  • Superconductors
  • III-V Semiconductors

III-V Semiconductors

Electrical Isolation in III-V Materials using ion implantation

Objectives

  • to use the data obtained from fundamental measurements to optimise present techniques used for isolation.
  • to develop technology to enable implant isolation to be expanded to the fabrication of devices for which no reliable method currently exists.
  • to offer any newly developed technology to users of the IBC, including industry.

Achievements

  • shown that 200°C implants of protons in GaAs produce high sheet resistances (108 ohms/square) with improved thermal stability compared with room temperature implants.
  • developed technology to produce sheet resistances of about 107ohms/square for both n-type and p-type InP and InGaAs.
  • industry using our improved technology for producing microwave devices/circuits.
  • work has been in collaboration with UCL and UMIST and includes the industrial partners, PRP Optoelectronics, Qinetiq and E2V Technologies.

This work was mostly supported by an EPSRC funded project - Future Technologies for the Electrical Isolation of III-V Semiconductor Devices. We developed techniques to produce resistivities of about 107ohm/square for both n-type and p-type InP and InGaAs, which is better than has ever been achieved before.

We have studied a wide range of ion species and ion doses as a function of the implant temperature, the material type and the doping density and have applied many of our findings to real devices, such as quantum well saturable absorbers and HBTs. All of our results have been communicated to our industrial collaborators and many have been published. More information can be found on the project pages.

Additionally, the work on III-V materials involves SMARTCUT of GaAs.