Chemical vapor deposition of heteroepitaxial Si1−x−yGexCy films on (100)Si substrates

Abstract

Thin heteroepitaxial films of Si1−x−yGexCy have been grown on (100)Si substrates using atmospheric pressure chemical vapor deposition at 625 °C. The crystallinity, composition, and microstructure of the SiGeC films were characterized using Rutherford backscattering spectrometry, secondary-ion-mass spectrometry, and cross-sectional transmission electron microscopy. The crystallinity of the films was very sensitive to the flow rate of C2H4 which served as the C source. Films with up to 2% C were epitaxial with good crystallinity and very few interfacial defects. Between 800 and 900 sccm of 10% C2H4 in He, the C content increased dramatically from 2% to 10% and the as-grown films changed from crystalline to amorphous. In order to establish deposition conditions for the crystalline-amorphous phase transformation, one SiGeC film was deposited as the 10% C2H4 flow was increased linearly from 500 to 1500 sccm during growth. When the C content reached ∼4%, the film developed considerable stacking defects and disorder, and at around 11% C, the film became amorphous.

Ion beams in silicon processing and characterization

“…These resonances are now used routinely at energies between 3 and 5 MeV to obtain depth profiles of O and C in a variety of samples such as high T c superconductors 147 and SiGeC layers on Si. 148 This extension of backscattering to higher energies is now accommodated in simulation programs.…”

Irreversible structural transformation of Si(1 1 4)-2 × 1 induced by subsurface carbon

“…Therefore, incorporation of isovalent C into the SiGe semiconductor alloy grown on Si substrates presents a possible substitute for the binary SiGe/Si system [1]. If C atoms can be added substitutionally into SiGe layers, the band gap will be increased and C atoms will compensate compressive strain caused by Ge, resulting in an increased critical film thickness [2][3][4]. A big obstacle, however, is in the fact that the solubility of C atoms in bulk Si is very low (less than 10 À3 %) due to the large difference in their atomic sizes [5].…”

Formation of compressively strained Si/Si1−xCx/Si(100) heterostructures using gas-source molecular beam epitaxy

“…Methods to grow Si 1 À x C x alloys using molecular beam epitaxy (MBE)-based techniques [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23], chemical vapor deposition (CVD) [11,[24][25][26][27][28][29][30], and solid phase epitaxy (SPE) [27,31,32] have been extensively studied. However, most of the previous studies were focused on pseudomorphic growths on Si substrate, and there have been only a limited number of investigations on the strain relaxation process during the heteroepitaxial growths of Si 1 À x C x crystalline films [15,22,23].…”