Differential-Hall Impurity Profiling of GaAs, Co-Implanted with Ga+, C+ and As+, C+
Abstract
Ion implantation is a relatively new method of doping GaAs semi- conductors but has been successfully used in devices with silicon substrates. It is a process by which impurity ions are accelerated by a particle accelerator and implanted into the substrate. The depth to which the impurity ions will penetrate is dependent upon the ion mass, energy of the beam and crystal orientation. After the implantation crystal lattice damage exists which must be annealed by heat treatment. This process is also used to electrically activate the impurity ions for conduction by moving them into the crystal sites. However, the annealing temperature required to effectively do the job exceeds the temperature where the GaAs surface begins to decompose. To prevent or reduce this effect the sample is encapsulated by a dielectric layer of Si3N4, approximately 1000 angstrom thick. This layer is placed on the sample after implantation and before annealing. The dielectric layer is etched away when electrical measurements are performed on the sample. The guarded van der Paul measuring system is used to acquire the crystal and Hall voltages of the samples. Electrical profiles are obtained on the 900 C annealed samples by a successive etching technique.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1977
- Accession Number
- ADA057362
Entities
People
- Michael Stefiniw
Organizations
- Air Force Institute of Technology