| Autor: |
S Kallel, B. Semmache, Ch. Dubois, Mustapha Lemiti, A. Laugier, H. Jaffrezic |
| Rok vydání: |
1998 |
| Předmět: |
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| Zdroj: |
Materials Science in Semiconductor Processing. 1:299-302 |
| ISSN: |
1369-8001 |
| Popis: |
In situ phosphorus-doped (P-doped) polysilicon (poly-Si) thin films are obtained by rapid thermal low pressure chemical vapor deposition (RTLPCVD) in a single chamber RTP machine by using diluted silane (SiH4/Ar=10%) and phosphine (PH3=200 ppm). Deposition kinetics of poly-Si films were studied in the 600–850°C temperature range at fixed total pressure of 2 mbar and gas flow rate (100 sccm). Activation energy of 1.82 eV was calculated in the surface reaction deposition regime. Dopant activation has been obtained sequentially by RTO at 1000°C in pure O2 atmosphere. This later process permits to both activate the phosphorus dopant and forms an ultrathin polyoxide which blocks dopant outdiffusion. Secondary ion-mass spectrometry (SIMS) analysis showed flat P-dopant profiles throughout the film thickness with a P concentration varying from 5.5×1020 to 2.4×1019 at/cm3 when the deposition temperature increases in the 600–850°C range. Grazing incidence X-ray diffraction (XRD) has been used to study the structural properties of the poly-Si layers. It appeared particularly that the amorphous to crystalline temperature transition occurs at around 650°C. Finally, four-point probe measurements showed that sheet resitivities in the mΩ cm range can be routinely achieved for in situ P-doped RTLPCVD poly-Si films. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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