Influence of the Ge Coverage Prior to Carbonization on the Structure of SiC Grown on Si(111)

Surface & Interface Analysis

Masri

et al. 2004

SiC/Si(111) heterostructures formed by using an alternative method for stress relaxation were investigated by SIMS and AES. The applied stress reduction method is based on a theoretical approach, which predicts an improvement of the SiC layer quality if Group IV elements are incorporated into the interface between SiC and Si. Germanium was chosen to test this approach. The incorporation of Ge into the heterointerface was carried out by depositing different amounts of Ge prior to the SiC growth process and varying the Ge deposition temperature. SIMS investigations revealed that Ge remains near the SiC/Si interface independently of the pre-deposited amount of Ge. In the case of two monolayers (ML) Ge coverage (with respect to the silicon surface) a surface segregation was observed. This indicates a limited transport of Ge to the SiC surface through the growing SiC layer due to grain boundary diffusion. At Ge coverages between 0.5 ML and 2 ML a sharper interface between the SiC and Si was observed. In this case the tail of the carbon distribution remains within the region occupied by the Ge distribution. The incorporation of Ge at the interface suppresses the out-diffusion of Si from the substrate to the surface of the growing SiC layer and, therefore, impedes the formation of voids at the SiC/Si interface.

Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

SIMS investigation of the influence of Ge pre‐deposition on the interface quality between SiC and Si

Pezoldt

Surface & Interface Analysis

Masri

et al. 2004

“…[45,57] As a consequence of the reduced stress in the initial conversion stages during the carbonization process of Si, the stress in the epitaxial 3C-SiC layer grown on top of these substrates is lowered and the crystalline quality is improved. [59,61] By increasing the Ge amount (≥1 ML), the stress keeps a decreasing behavior but the crystalline quality is deteriorated.…”

Section: C-ge-si Layer With Sic Formationmentioning

confidence: 99%

“…For this purpose, Ge [42][43][44][45][46][47][48][49][50][51][52][53][54][55] or antimon (Sb) [56] were applied to improve the 3C-SiC nucleation and the 3C-SiC interface quality. In previous works, [57][58][59][60][61][62][63] it has been demonstrated that, if Ge impurity was predeposited onto the Si surface prior to the carbonization, the residual stress inside the 3C-SiC layer, as well as the reverse currents of the SiC/Si heterojunction and the void density at the interface can be significantly reduced. In addition to the aforementioned results, it has been shown that by introducing Ge, the crystalline quality could be improved.…”

Section: Introductionmentioning

confidence: 99%

Chemoheteroepitaxy of 3C‐SiC(111) on Si(111): Influence of Predeposited Ge on Structure and Composition

Physica Status Solidi (a)

Lubov

Kulikov

et al. 2021

Self Cite

Secondary ion mass spectroscopy, Fourier transformed infrared spectroscopy, ellipsometry, reflection high energy diffraction and transmission electron microscopy are used to gain inside into the effect of Ge on the formation of ultrathin 3C‐SiC layers on Si(111) substrates. Accompanying the experimental investigations with simulations it is found that the ultrathin single crystalline 3C‐SiC layer is formed on top of a gradient Si1–x–yGexCy buffer layer due to a complex alloying and alloy decomposition processes promoted by carbon and germanium interdiffusion and SiC nucleation. This approach allows tuning residual stress at very early growth stages as well as the interface properties of the 3C‐SiC/Si heterostructure. Useful yields of secondary ions of Ge in Si matrix and Si dimer are estimated.

“…Unfortunately, growth experiments carried out between 2 and 4 ML of Ge predeposition led to deteriorated surfaces that had detrimental effects on the subsequent epitaxial growth. 15,16 These experimental findings indicate that Ge behaves as an active diffusion barrier, which improves the crystal quality and the electrical properties. Such secondary effects can lead to an opposite effect of the Ge precoverage.…”

mentioning

confidence: 94%

Raman studies of Ge-promoted stress modulation in 3C–SiC grown on Si(111)

Applied Physics Letters

McNeil

Kazan

et al. 2005

We present a study of the stress state in cubic silicon carbide (3C–SiC) thin films (120 and 300 nm) grown by solid-source molecular-beam epitaxy (SSMBE) on Si(111) substrates modified by the deposition of germanium prior to the carbonization of Si. μ-Raman measurements were used to determine the residual stress existing in the 3C–SiC layers. The stress is found to decrease linearly with increasing Ge quantity but with different strength depending on the 3C–SiC thickness deposited after the introduction of Ge. Based on secondary ions mass spectroscopy (SIMS) and transmission electron microscopy (TEM) analyses it is suggested that the Ge introduced prior to the carbonization step remains in the near-interface region and reduces the Si outdiffusion, which further reduces the stress state of the 3C–SiC layers.