Defect generation in silicon-implanted gate insulators of insulated gate field-effect transistors

• Published in: Journal of applied physics 1989-12, Vol.66 (12), p.5801-5804
• Main Authors: SUNE, C. T, REISMAN, A, WILLIAMS, C. K
• Format: Article
• Language: English
• Subjects: Applied sciences; Electronics; Exact sciences and technology; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Transistors
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.343650

In this paper, the effects on insulated gate field-effect transistor device characteristics due to implantation of silicon into the gate insulator have been studied. Contrary to what one might have expected in an oxygen-deficient insulator, the primary defects generated, as detected by optically assisted injection of electrons into the gate insulators of damaged devices, are large quantities, as much as 1.3×1012 cm−2, of neutral electron traps (NET). Secondary types of defects found appear to be fixed negative charge, approximately 2.3×1011 cm−2 in the worse case, and a smaller amount of fixed positive charge (FPC), approximately 1.7×1011 cm−2 in the worse case. It was found that none of these defects could be removed by employing conventional postmetal annealing conditions in forming gas (10% H2, 90% N2) at 400 °C for up to 60 min. The defects created by ion implantation appear to be quite different from those created by x-ray or electron irradiation, where large quantities of FPC and NET are generated which can be annealed in a similar postmetal annealing cycles.