Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9567289 | Applied Surface Science | 2005 | 4 Pages |
Abstract
The influence of surface pretreatments by remote hydrogen and/or argon plasma on the silicon nucleation density on thermally grown SiO2 in the early stages of low pressure chemical vapor deposition (LPCVD) using monosilane (SiH4) has been studied to control the areal density of Si quantum dots (Si-QDs) on SiO2. In the remote H2 (or D2) plasma treatments prior to SiH4-LPCVD, the formation of SiOH (SiOD) surface bonds, which act as reactive sites, was confirmed from no changes in the SiO2 surface microroughness and in the thickness. In fact, by a H2 plasma pretreatment, the areal density of Si-QDs as high as 7Â ÃÂ 1010Â cmâ2 was obtained in the LPCVD condition of the dot density with as low as 6Â ÃÂ 108Â cmâ2 on as-grown SiO2. By changing the pressure and the substrate temperature in the H2 plasma pretreatment, the dot density was controlled in the range of 4Â ÃÂ 109 to 7Â ÃÂ 1010Â cmâ2. Further increase in the dot density and improvement of the dot size uniformity was also demonstrated by the pretreatment of Ar plasma followed by H2 plasma, presumably because of improved uniformity and integrity in SiO2 surface coverage with OH bonds just before LPCVD.
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Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
K. Makihara, H. Deki, H. Murakami, S. Higashi, S. Miyazaki,