Ion mixing of semiconductor superlattices
Abstract
Compositional disordering of III-V compound superlattice structures has received considerable attention recently due to its potential application for photonic devices. The conventional method in induce compositional disorder is to implant a moderate dose of impurity ions (approx. 10 (exp 15)/sq cm) into the structure at room temperature, followed by a high temperature annealing step (this process is referred to as IA here). Ion irradiation at room temperature alone does not cause any significant intermixing of layers. The subsequent high temperature annealing step tends to restrict device processing flexibility. Ion mixing (IM) is capable of enhancing compositional disordering of layers at a rate which increases exponentially with the ion irradiation temperature. As a processing technique to planarize devices, ion mixing appears to be an attractive technology. Compositional disordering was studied disordering in the AlGaAs/GaAs and the InGaAs/InP systems using ion mixing. It was found that the ion mixing behavior of these two systems shows a thermally activated regime as well as an athermal regime, similar to that observed for metal-metal and metal-semiconductor systems. Ion mixing is observed to induce compositional disordering at significantly lower temperatures than that for the IA process. The two processes were compared in terms of five parameters (1) irradiation temperature, (2) dose dependence (3) annealing, and (4) electrically active ions. It was found that the IM process is more efficient in utilizing the defects generated by ion irradiation to cause disordering. Both the physical mechanism of ion mixing and possible device implications will be discussed.
- Publication:
-
Presented at the 7th International Conference on Ion Beam Modification of Materials
- Pub Date:
- 1990
- Bibcode:
- 1990imbb.conf....9X
- Keywords:
-
- Ion Beams;
- Ion Implantation;
- Irradiation;
- Mixing;
- Semiconductors (Materials);
- Superlattices;
- Aluminum Arsenides;
- Gallium Arsenides;
- Indium Arsenides;
- Indium Phosphides;
- Order-Disorder Transformations;
- Solid-State Physics