Invited; Epitaxy and heterostructure of germanium tin-related group-IV alloy semiconductors for future electronic and optoelectronic applications

GeSn and related group-IV alloys have been much attracted as one of novel semiconductor materials for nextgeneration nanoelectronics, optoelectronics, and thermoelectronics applications. GeSn semiconductor promises high carrier mobility, highly efficient optoelectronic conversion, low thermal conductivity, and also low thermal budget process those properties are appropriate for the integration on Si ULSI platform. On the other hand, there are some challenges for practical applications of GeSn thin films integrating into Si ULSI. One is realizing a high substitutional Sn content over several percents in GeSn and related alloys, since the thermal equilibrium solid-solubility of Sn in Ge is as low as 1% (0.1% in the case of Si). In addition, the strain control of GeSn heteroepitaxial layers with a high crystalline quality is required for energy band engineering. Thus, it is necessary to understand and establish the crystal growth science and technology of GeSn-related group-IV thin films to control those crystalline and electronic properties. Please click Download on the upper right corner to see the full abstract

Growth and applications of GeSn-related group-IV semiconductor materials

We review the technology of Ge1−xSnx-related group-IV semiconductor materials for developing Si-based nanoelectronics. Ge1−xSnx-related materials provide novel engineering of the crystal growth, strain structure, and energy band alignment for realising various applications not only in electronics, but also in optoelectronics. We introduce our recent achievements in the crystal growth of Ge1−xSnx-related material thin films and the studies of the electronic properties of thin films, metals/Ge1−xSnx, and insulators/Ge1−xSnx interfaces. We also review recent studies related to the crystal growth, energy band engineering, and device applications of Ge1−xSnx-related materials, as well as the reported performances of electronic devices using Ge1−xSnx related materials

Optoelectronic properties of high-Si-content-Ge 1 −x – y Si x Sn y /Ge 1− x Sn x /Ge 1− x–y Si x Sn y double heterostructure

The optoelectronic properties of Ge1−x−ySixSny/Ge1−xSnx/Ge1−x−ySixSny doubleheterostructures pseudomorphically grown on a Ge substrate were investigated. Thephotoluminescence (PL) intensity of the sample with Ge0.66Si0.23Sn0.11 cladding layers is threetimes larger compared to PL from structure with a Ge cladding layer, which can be attributed tohigher energy band offsets at both conduction and valence band edges at theGe0.91Sn0.09/Ge0.66Si0.23Sn0.11 interface. The PL spectrum of the sample with theGe0.66Si0.23Sn0.11 cladding layer at room temperature can be deconvoluted into four components,and the origins of these components can be assigned to direct and indirect transitions bymeasuring the temperature dependence of each component’s intensity. In addition, we examinedthe formation and characterization of strain-relaxed Ge1−x−ySixSny/Ge1−xSnx/Ge1−x−ySixSnydouble heterostructures to relieve the compressive strain in the Ge1−xSnx layer. Stacking faultswere observed in the Ge1−xSnx and Ge1−x−ySixSny layers. The PL peak intensity of the strainrelaxedGe1−xSnx layer decreases by a factor of 1/20 compared to the PL peak intensity of thedouble heterostructure pseudomorphically grown on a Ge(001) substrate. In addition, PLintensity can be increased by post-deposition annealing owing to decreasing defects

Growth and applications of GeSn-related group-IV semiconductor materials

We review the technology of Ge(1−x)Sn(x)-related group-IV semiconductor materials for developing Si-based nanoelectronics. Ge(1−x)Sn(x)-related materials provide novel engineering of the crystal growth, strain structure, and energy band alignment for realising various applications not only in electronics, but also in optoelectronics. We introduce our recent achievements in the crystal growth of Ge(1−x)Sn(x)-related material thin films and the studies of the electronic properties of thin films, metals/Ge(1−x)Sn(x), and insulators/Ge(1−x)Sn(x) interfaces. We also review recent studies related to the crystal growth, energy band engineering, and device applications of Ge(1−x)Sn(x)-related materials, as well as the reported performances of electronic devices using Ge(1−x)Sn(x) related materials

Characterization of Defect Traps in SiO2 Thin Films

In order to understand the degradation of the electrical operations of metal-oxide-semiconductor (MOS) devices, this work is concerned by the defects generation processes in the non-stoichiometric SiOx, area and at the SiO2 interface. For this purpose, a new measurement technique to study slow-state traps and their relationship with fast-state traps is developed. This method considers capacitance-voltage measurements and temperature effects during the hysteresis cycle