Ultra-doped semiconductors made by non-equilibrium processing for electronic,photonic and spintronic applications IV

Doping is the key to make semiconductors functional. This symposium is devoted to ultra-doping or hyperdoping, i.e. the introduction of dopant or impurity concentrations far above the solid solubility limits. The resulting materials may exhibit very interesting (opto)electronic, magnetic or superconducting properties.

Scope:

In 1931, Wolfgang Pauli said “One shouldn’t work on semiconductors, that is a filthy mess; who knows whether any semiconductors exist”. We know it is doping that makes semiconductor visible and functional. Doping is the intentional introduction of impurities into an intrinsic semiconductor for the purpose of modulating its electrical, optical, and structural properties. It is the indispensable step in the integrated-circuit industrial production line. Ultra-doping or hyperdoping of semiconductors refers to introducing dopant concentrations far above the solid solubility limits. This leads to the broadening of dopant energy level into a separated or merged impurity band with interesting consequences in terms of optoelectronic, magnetic or superconducting properties. Here, the dopants also include those elements that are far away from the host semiconductor in the element table and have large ionization energies. By hyperdoping, semiconductors can be turned to metals, alloys, or superconductors (such as boron doped diamond/Si/Ge), or ferromagnets (such as Mn doped III-V compounds). The applications spread from electronics, spintronics, quantum technology to optoelectronics, with the first practical devices appearing recently. To overcome the solid solubility limit, methods far away from thermal equilibrium are used. Ion implantation, low-temperature molecular beam epitaxy, and chemical vapor deposition are eventually associated to flash lamp, nanosecond laser annealing and/or microwave annealing, to minimize post-doping thermal budget and diffusion. Even so, it is still a question if the introduced dopants are randomly distributed in the appropriate lattice positions. Therefore, proper atomic- scale characterization is also needed to verify the dopant distribution and chemical states. This symposium will be highly interdisciplinary, attracting participants from semiconductor, nanoelectronics, optoelectronics, plasmonics, superconductivity and magnetism communities.

Hot topics to be covered by the symposium:

• Optoelectronic devices based on hyperdoped Si, Ge, III-V and GeSn including photodetectors at infrared wavelength
• Hyperdoped semiconductors (Si, Ge and III-V) for plasmonics: tunable plasmonic frequency by doping concentration, plasmonic structural design
• Highly doped semiconductors (Si, Ge, SiGe and GeSn) for future field-effect transistors
• Highly mismatched alloys, such as GeSn, SiGeSn, GaAsN, GaPN …
• Ferromagnetic semiconductors, including transition metal doped III-V and IV semiconductors and their structural characterization
• Diamond, Si, Ge and SiC based superconductors: Boron doping, superconducting properties, applications for quantum technology
• Manufacturing hyperdoped and mismatched materials: ion implantation, low-temperature molecular beam epitaxy, low-temperature chemical vapor deposition
• Fast thermal annealing, pulsed laser melting and flash lamp annealing on semiconductors and metals
• Advanced characterization technologies for impurities and defects at atomic scale: including Atom probe tomography , High resolution transmission electron microscopy, Rutherford backscattering/channeling, Emission channeling, X-ray spectroscopies, near field techniques
• First-principle calculations regarding the impurity and defect configuration, role of interfaces, phonon spectra, electron-phonon interaction
• Challenges for doping emerging materials, such as 2D semiconductors, ultra-wide bandgap semiconductors and topological insulators
• New concepts for doping