Optimization of LPCVD phosphorous-doped SiGe thin films for CMOS-compatible thermoelectric applications

Abstract

The incessant downscaling of building blocks for memory and logic in computer chips requires energy-efficient devices. Thermoelectric-based temperature sensing, cooling as well as energy harvesting could be useful methods to reach reliable device performance with stable operating temperatures. For these applications, complementary metal–oxide–semiconductor (CMOS)-compatible and application ready thin films are needed and have to be optimized. In this work, we investigate the power factor of different phosphorous-doped silicon germanium (SiGe) films fabricated in a 300 mm CMOS-compatible cleanroom. For the thermoelectric characterization, we used a custom-built setup to determine the Seebeck coefficient and sheet resistance. For sample preparation, we used low pressure chemical vapor deposition with in situ doping and subsequent rapid thermal annealing on 300 mm wafers. Thin film properties, such as film thickness (12–250 nm), elemental composition, crystallinity, and microstructure, are studied via spectroscopic ellipsometry, x-ray photoelectron spectroscopy, x-ray diffraction, atomic force microscopy, and TEM. The SiGe-based thin films vary in the ratio of Si to Ge to P and doping concentrations. A power factor of 0.52 mW/m K2 could be reached by doping variation. Our results show that SiGe is a very attractive CMOS-compatible material on the 300 mm wafer level and is immediately ready for production of thermoelectric embedded applications.

Realization of low potential barrier in MoS2/rGO heterojunction with enhanced electrical conductivity for thin film thermoelectric applications

“…The figure 1(a) shows Raman spectra of peaks at 380 and 406 cm −1 corresponds to E g 2 1 [Γ] and A g 1 [Γ] vibrational modes, confirms the formation of MoS 2 . The A g 1 mode is the out of plane vibration of S atoms and E g 2 1 represents the inplane vibration of Mo -S atoms. The frequency difference (Δω) of 26 cm −1 , reveals the bulk nature of MoS 2 .…”

Stabilizing Antiferroelectric‐Like Aluminum‐Doped Hafnium Oxide for Energy Storage Capacitors

“…[ 14,15 ] While the peak at 28.5° is attributed to monoclinic phase, m(11), we also have the presence of polysilicon which has peaks at 28.3, 46.5, 55.2° referenced by the green dotted lines in the plot. [ 16 ] The polysilicon acts as an electrically conducting top electrode. It is possible that there is a small contribution of the monoclinic phase of HfO 2 present, which could lead to nonoptimal ferroelectric properties.…”

Recent Advances in the Nanomaterials, Design, Fabrication Approaches of Thermoelectric Nanogenerators for Various Applications

“…[14] Polymer-based and carbon-based TE materials may be tuned to be either n-type or p-type with n-type and p-type doping, respectively. [15,16] By doping smaller elements like phosphorus (n-type) or boron (p-type) into the crystal lattice of TE materials, the charge carrier concentration increases, resulting in a higher PF. Such doping usually requires fairly large concentrations above 5% to have significant effects.…”