Reduction of interfacial tunnel defects in silicon due to chemical vapor deposition of tungsten

• Published in: Applied physics letters 1987-08, Vol.51 (8), p.602-604
• Main Authors: DE BLASI, J. M, DELFINO, M, SADANA, D. K, RITZ, K. N, NORCOTT, M. H
• Format: Article
• Language: English
• Subjects: Applied sciences; Electronics; Exact sciences and technology; Microelectronic fabrication (materials and surfaces technology); Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.98360

A method is reported for reducing tunnel formation in p+-n Si, and a correlation is shown between tunnel defects and junction leakage. 11B+-implanted Si annealed for 30 min at 900 °C in N2 and subsequently deposited with W forms a high density of filamentary tunnel defects extending on the order of 0.1 μm from the W/Si interface. Reverse-bias leakage of 0.33-μm-deep junctions is −90 nA/cm2 at −5 V and the forward-bias ideality is 1.24 over eight decades of current. By contrast, for 11B+-implanted Si oxidized for 7 min in steam, tunnels if present are less than 0.01 μm in length. The reverse-bias leakage is −0.3 nA/cm2 at −5 V and the forward-bias ideality is 1.00. The 2×1019 cm−3 interfacial carrier concentration is the same for both deposits.