Details

Autor(en) / Beteiligte

• Rakheja, S.
• Huang, L.
• Hau-Riege, Stefan
• Harrison, S. E.
• Voss, Lars F.
• Conway, Adam M.

Titel

Performance Modeling of Silicon Carbide Photoconductive Switches for High-Power and High-Frequency Applications

Ist Teil von

• IEEE journal of the Electron Devices Society, 2020-01, Vol.8, p.1118-1128

Ort / Verlag

New York: IEEE

Erscheinungsjahr

2020

Link zum Volltext

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• In this article, we focus on the physical modeling of the nonlinear operation of intrinsic photoconductive semiconductor switches (PCSS) based on 4H-SiC using coupled electrical and optical simulations to provide performance bounds of the switch as a function of material and geometry parameters, as well as applied bias. We also conduct a full design-space exploration to identify the optimal operating and design conditions to maximize the compound metric <inline-formula> <tex-math notation="LaTeX">f_{\mathrm {op}} P_{\mathrm {out}} </tex-math></inline-formula>, where <inline-formula> <tex-math notation="LaTeX">f_{\mathrm {op}} </tex-math></inline-formula> is the maximum operating frequency, and <inline-formula> <tex-math notation="LaTeX">P_{\mathrm {out}} </tex-math></inline-formula> is the maximum output power the switch can provide. We quantify that a 10-<inline-formula> <tex-math notation="LaTeX">\mu \text{m} </tex-math></inline-formula> long and 5-<inline-formula> <tex-math notation="LaTeX">\mu \text{m} </tex-math></inline-formula> thick 4H-SiC PCSS can deliver output power density greater than 2W/mm at 150 GHz when triggered by a 0.325-<inline-formula> <tex-math notation="LaTeX">\mu \text{m} </tex-math></inline-formula> laser with intensity of 3 kW/cm 2 . The output power density can be significantly enhanced by increasing the optical generation rate as well as by using thicker SiC to improve its absorption characteristics. A brief discussion of signal distortion and electrostatic screening effects at high optical bias is included. Finally, we present an analytic model of charge cloud propagation and the frequency of operation based on the physics, material parameters, and geometry of the PCSS. The model accurately captures <inline-formula> <tex-math notation="LaTeX">f_{\mathrm {op}} </tex-math></inline-formula> of 4H-SiC PCSS over a broad range of laser spot size, device length, and electrical bias applied at the contacts.