ETD

• cmos-compatible devices
• cryogenic electrical characterization
• double-barrier quantum well
• fem modeling
• ge-rich sige heterostructures
• group-iv semiconductors
• quantum devices
• quantum transport
• resonant tunneling diodes
• semiconductor microfabrication
• terahertz technology
• tunneling effect
• vertical transport

Terahertz technology is a promising frontier between electronics and photonics, with potential applications in wireless communications, imaging, and sensing. This thesis investigates n-type Ge-rich SiGe resonant tunneling diodes as CMOS-compatible candidates for terahertz generation. Compared with conventional Si-rich designs, Ge-rich heterostructures offer a more favorable band alignment and a lower electron effective mass, potentially enabling more efficient tunneling transport and improved device performance. The work combines heterostructure design, microfabrication, finite-element modeling, and electrical characterization. A reduced analytical model and numerical simulations were developed to study current spreading and bias uniformity, showing how device geometry strongly affects transport across the active region. On this basis, circular and rectangular mesa architectures were fabricated and measured. The experimental and numerical results clarified the role of contacts, lateral current distribution, and band profile in determining device behavior, and provided clear guidelines for further heterostructure and geometry optimization. Overall, this work contributes to the development of Ge-rich SiGe resonant tunneling diodes and supports their potential as silicon-compatible terahertz devices.