High-quality gate-oxide films for MOSFET's deposited by oxygen-argon sputtering

Abstract High-quality silicon dioxide films for MOSFET gates are succesfully obtained by oxygen-argon sputter deposition at low temperature (200°C). This paper presents the excellent effects of mixing oxygen with the argon sputtering gas on the bulk and MOS interface properties of silicon dioxide films as well as related mechanisms. Oxygen mixing considerably improves the bulk properties of resistivity and breakdown field over those of argon-only sputter-deposited films (from 10 12 to > 10 15 Ω cm and from 2 to > 8 MV/cm, respectively). The field effect mobility is also improved from 250 to 700 cm 2 /V.s. These values obtained by the oxygen mixing are almost the same as for high temperature thermal dioxide films (1000°C). These improvements are suggested to be a result of enhancement of surface migration of deposited particles, and/or protection by chemisorbed oxygen surface layers of the silicon substrate and the film surface from direct bombardment by high-speed argon particles.

[1]  W. Fichtner,et al.  Experimental results on submicron-size p-channel MOSFET's , 1982, IEEE Electron Device Letters.

[2]  I. Johansen.  Electrical Conductivity in Evaporated Silicon Oxide Films , 1966 .

[3]  H. F. Winters,et al.  Effect of Oxygen on the rf-Sputtering Rate of SiO2 , 1968 .

[4]  A. Lakhani.  Device-quality SiO2 films on InP and Si obtained by operating the pyrolytic CVD reactor in the retardation regime , 1984 .

[5]  H. F. Winters,et al.  Sputtering of chemisorbed gas (nitrogen on tungsten) by low‐energy ions , 1974 .

[6]  R. E. Jones,et al.  Re-emission of sputtered SiO 2 , during growth and its relation to film quality , 1970 .

[7]  T. Serikawa,et al.  Electrical conduction and dielectric breakdown in sputter‐deposited silicon dioxide films on silicon , 1987 .

[8]  L. Terman.  An investigation of surface states at a silicon/silicon oxide interface employing metal-oxide-silicon diodes , 1962 .

[9]  Y. Taga,et al.  Anomalous Etching Phenomenon of RF-Sputtered SiO2 Films , 1979 .

[10]  T. Serikawa,et al.  Magnetron‐Sputtered SiO2 Films in Hydrogen‐Argon Mixtures , 1984 .

[11]  W. A. Pliskin.  Comparison of properties of dielectric films deposited by various methods , 1977 .

[12]  A. S. Grove,et al.  Electron and hole mobilities in inversion layers on thermally oxidized silicon surfaces , 1965 .

[13]  H. F. Winters.  Sputtering of Chemisorbed Nitrogen with Ar , 1971 .

[14]  T. Serikawa,et al.  The Effects of Oxygen‐Argon Mixing on Properties of Sputtered Silicon Dioxide Films , 1987 .

[15]  Multiple Source Moiré Patterns with Photographic Diffraction Gratings , 1966 .

[16]  S. M. Sze,et al.  Physics of semiconductor devices , 1969 .