Composition measurement of paraelectric SrTiO3 layer |
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| Authors: | Tohru Hara Motoyasu Sugiyama Shin-Chang Chen |
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| Affiliation: | 1. Electrical Engineering Hosei University , Kogonei, Tokyo, 184, Japan;2. VLSI R&3. D Center Oki Electric Industry Co. Ltd., Higashiasakawacho , Hachioji, Tokyo, 193, Japan |
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| Abstract: | Abstract Since composition is an important parameter affecting the dielectric properties in paraelectric SrTiO3 layers, composition is determined by Rutherford backscattering spectrometry (RBS) measurement. In this measurement, specifically for achieving precise composition measurement, the RBS spectra of Sr, Ti and O must be separated individually. This spectrum separation can only be attained when thin (800 Addot] thick) SrxTiOy layers are deposited on graphite substrate. The measurement is performed for layers deposited at different O2 partial pressure ratios and sputtering pressures. This measurement indicates that composition of O, y, in SrxTiOy layer decreases from 3.7 to 2.7 with the decrease of O2 partial pressure raito, R(=O2/O2 + Ar) from 1.0 to 0.83. Composition of Sr, x, also changes from 1.1 to 0.6 with this change. With the decrease of sputtering pressure from 10 to 5 mTorr, however, composition, y, is held at 2.7 and only the composition, x, increases from 0.6 to 1.1. This composition measurement is useful for the deposition of optimized dielectric layer employed in the charge storage capacitor. |
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| Keywords: | RBS dielectric layer SrTiO3 composition measurement sputtering |
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