Optimization of InP / Si heteroepitaxial growth conditions using organometallic vapor phase epitaxy

• Published in: Journal of crystal growth 1989-06, Vol.96 (2), p.369-377
• Main Authors: Yamamoto, Akio, Uchida, Naoto, Yamaguchi, Masafumi
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Physics; Solid surfaces and solid-solid interfaces; Surface and interface dynamics and vibrations; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/0022-0248(89)90535-6

Heteroepitaxial growth of InP on Si by organometallic vapor phase epitaxy has been studied. The two-step growth method is employed to grow InP directly on Si substrates, and the study is focused on the optimization of 1st InP layer growth conditions. Growth temperature and pH 3/TMI ratio are found to be the most dominant factors for 1st InP layer growth. The optimum growth temperature is around 350°C. For an InP film grown at 350°C, lattice reconstruction and grain growth are clearly observed after the annealing near the 2nd layer growth temperature ( ∼ 600 ° C). Higher temperatures than the optimum growth temperature bring about a random nucleation and consequently discontinuous film growth. The lower limit of growth temperature results from the lack of phosphorus atoms due to the low PH 3 decomposition rate. A higher PH 3/TMI ratio enables us to grow a high-quality 1st InP layer at a lower temperature. By optimizing these 1st layer growth conditions, the FWHM of the X-ray rocking curve for a 2nd grown layer is reduced to 400 arcsec and the photoluminescence intensity is also increased to about 1/3 of that for a homoepitaxial InP layer. Using heteroepitaxial InP films, a thin film solar cell has been fabricated on a Si substrate. The conversion efficiency for the present cell is about 3%. Problems to be solved to increase conversion efficiency are also discussed.