IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Surface Science Tuesday Sessions
       Session SS1-TuP

Paper SS1-TuP3
Reduction of Oxidation Rate during the Initial Stages of the Oxidation of Heavily Phosphorus Doped Silicon in Dry Oxygen

Tuesday, October 30, 2001, 5:30 pm, Room 134/135

Session: Semiconductor Surfaces Poster Session
Presenter: Y. Kamiura, Osaka Prefecture University, Japan
Authors: Y. Kamiura, Osaka Prefecture University, Japan
K. Hasegawa, Osaka Prefecture University, Japan
Y. Mizokawa, Osaka Prefecture University, Japan
K. Kawamoto, Denso Co. Ltd., Japan
Correspondent: Click to Email
The oxidation of heavily phosphorus doped Si(100) and polycrystalline Si in RT to 800°C range in dry oxygen was studied by Auger electron spectroscopy(AES). The oxidation rate of the phosphorus doped Si(100) was larger than the P-doped poly-Si for each O@sub 2@ exposure at RT. Phosphorus segregation didn't take place in RT oxidation of the P-doped Si(100). The Dioxide formation gradually occurred from ca. 500L in thermal oxidation at 650°C in the P-doped Si(100). The reduction of oxidation was found above 5x10@super 5@L. At the same time, the amount of the phosphorus piled-up at Si/SiO@sub 2@ interface slightly degreased. The accurate AES measurements of 97 to 137eV range showed that phosphorus slightly oxidized in the initial stage of the oxidation of P-doped Si for each O@sub 2@ exposure and the phosphorus peak in P@sub 2@O@sub 5@ was clearly found at ca. 110eV above 10@super 3@L. It seemed that the modification of this substance fairly desorbed in UHV and the residual partially held into the Si/SiO@sub 2@ interface at this temperature. Therefore the oxidation of silicon didn't proceed until about ca. 1x10@super 6@L. On the other hand, the suppression of oxidation of silicon wasn't caused for P-doped poly-Si, the amount of SiO@sub 2@ strongly increased above 5x10@super 5@L. The thermal oxidation behavior at 800 °C was quite different from low temperature results. Oxygen uptake on the silicon surfaces didn't almost take place below 10@super 3@L for both samples because the volatile SiO molecules were formed and the silicon surfaces were etched away by oxygen atoms. Dioxide formations rapidly took place above 10@super 4@L, and then a large amount of phosphorus piled up at the interfaces due to the formation of SiO@sub 2@. The P@sub 2@O@sub 5@ was formed through low O@sub 2@ exposures even at this temperature for both samples.