砷化镓中质子注入之研究

本文中,我们研究了砷化镓中质子注入及退火恢复过程。实验用晶向<100>偏1—3°,掺Sn 5×10¹⁷-1×10¹⁸cm^-3的单晶,室温下质子注入,注入能量E约8×10⁴—2×10⁶eV,用A-B腐蚀剂对注入质子样品的解理面显结,测得质子注入高阻层的纵向深度x_j和径向扩展x_L与注入能量E的定量关系。然后,对注入质子样品,在150—800℃下退火5分钟,用双晶衍射仪研究了样品的应变恢复过程,在静电计上测量了高阻阻值随退火温度的变化。根据实验结果,讨论了砷化镓中质子注入的射程R_p,电子阻止本领S_n(E)和核阻止本领S_e(E),以及质子注入形成高阻和退火恢复的机理。关键词：

A STUDY OF PROTON IMPLANTATION FOR GaAs

In this paper, a study has been made of proton implantation and annealing behavior of GaAs. The single crystal wafers used in the implantation were oriented typically at 1-3° away from (100), and doped with Sn to 5×10¹⁷-1×10¹⁸cm^-3. The implantation was carried out at room temperature in a proton accelerator and ion implantation machine with an energy of 8×10⁴-2×10⁶eV. Following bombardment, the implanted area was delineated by means of an A-B etchant, and the penetration depth of proton x_j was determined. The x_j values obtained can be related to the implantation energy E as follows x_j= (8.716×10^-4+4E^-1)E^1.365,where X_j is in ?, E in eV. The maximum lateral spread of the proton X_L as a function of energy was also, determined, and found to be ～10⁴? when E>3×10⁵eV. The proton implanted samples were annealed at 150-800℃ for 5 min. A X-ray double crystal difractrometer was used to characterize the recovery of strain, and a electrometer was used to determine the resistance variation with annealing temperature. The results showed that the critical dose φ^* for amorphous layer formation after proton implantation was ～10¹⁶cm^-2, and the recovery of strain began at 150°, and virtually stopped at 450°. In the temperature range 150-450°, there were no significant variation in implanted resistance. The recovery of resistance oecurred only at higher temperatures. The project range of proton R_p, the electron stopping power S_e(E), the nuclear stopping power S_n(E), and the mechanism of annealing of implanted proton in GaAs are discussed on the basis of the present experimental results.
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