DST-NRF Centre of Excellence in Strong Materials Diamond, Thin Hard Films & Related Materials

Implantation of N-O in Diamond

T.Matindi, Dr. S.R. Naidoo

Outline

• Introduction• Aim and objectives • Experimental techniques• Characterization techniques• Summary and conclusions

Introduction

• Properties of diamond :

Large energy gap around 5.5 eV. High carrier mobilities. High breakdown field strength. Highest thermal conductivity. Low dielectric constant. Broad optical transparency from UV to IR

Some potential application of diamond

Function Field of application

High temperature semiconductor Automobile and aircraft engines

High frequency/high power transistors High speed transistors, High speed data process

High voltage transistors Electric power control

X-ray windows IR windows

X-ray lithography masks and IR windows

Light emission LEDs and laser in UV region, white luminescence and light source for printers.

Pressure sensing Pressure sensor at high temperature

Conditions for manufacturing diamond-based electronic devices

P-type doping diamond (achieved using boron as an acceptor impurity)

N-type doping diamond (achieved using phosphorus)

Shallow dopants (both are substitutional dopants and are deep lying acceptor and donor states.)

Activation energies for some impurities in diamond.

The doping of diamond

N-dopingPhosphorusNitrogen

P-dopingBoron

• Substitution of N-O into the diamond lattice is suggested to induce a shallow defect level below the conduction band edge which leads to n-type conductivity [1].

[1]. J. Lowther, “Substitutional oxygen-nitrogen pair in diamond,” Physical Review B, vol. 67, no. 11, p. 115206, 2003.

Theoretical work

Aim and objectives

• To explore the possibility of achieving n-type conductivity in diamond.

• To do the implantation of N-O into the diamond lattice.

• To investigate the interaction between nitrogen and oxygen in the diamond as well the related defects.

Experimental techniques

Ion implantation:

The 200-20A2F ion implanter (iThemba LABS, Gauteng)

Ions : Nitrogen and Oxygen.

Energy range : from 10 keV to 170 keV.

Fluences ranging: from ions/ to ions/.

• Optical spectroscopy.

• Electronic measurements.

Characterization techniques

Summary and conclusions

• To explore the possibility of achieving n-type conductivity in diamond.

• To do the implantation of N-O into the diamond lattice.

• To investigate the interaction between nitrogen and oxygen in the diamond as well the related defects.

• Optical spectroscopy and electronic measurements

Thank you

Merci

Setup for the generation of the VUV laser light