Dry etch damage in III–V semiconductors

✍ Scribed by Evelyn L. Hu; Ching-Hui Chen

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 478 KB
• Volume: 35
• Category: Article
• ISSN: 0167-9317
• DOI: 10.1016/s0167-9317(96)00123-2

✦ Synopsis

There has been steady progress in understanding the propagation of low energy, ion-induced damage into semiconductor substrates. Specially designed hetemstructure (quantum well) substrates allows us to trace the profile of damage into the material. A number of experiments have highlighted the surprisingly deep damage profiles resulting from low energy ion bombardment (e.g. >10O0A deep for incident ions energies ~ 300 eV ). Theoretical simulations have shown the important role played by fottuitons scattering of incident ions into channeling directions, producing the deep damage profiles. Recent experiments have also shown the importance of rapid diffusion of ion-created defects. Using a model that includes the effects of both channeling and defect diflhsion, CHANDID (CHanneling ANd Diffusion in Ion Damage), we have deduced a room temperature diffusion constant (f D ~ Ix 10 -15 cm2/sec. One cause of this unusually high value of D may be attributed to radiation diffusion: the creation of excess electrons and holes during the etch process whose subsequent non..radiafive recombination transfers momentum to the defects. Preliminary experiments in both GaAs and haP employing above-band-gap illumination during ion bombardment, validate this picture. Such understanding, of intrinsic importance, can be used to design material and device structures in which the effects of ion damage may he mitigated.