The US Army Research Lab seeks a partner to commercialize a new heterobarrier varactor device structure that accounts for polarization effects and exhibits a symmetric C-V plot at zero bias.
Vertical hetero structures enable high-frequency, high-power RF devices, where the vertical nature of the electronic transport allows for large surface area and thus high current. Specifically, high-performance variable capacitors based on vertical heterostructures can be implemented through a pair of oppositely stacked polar semiconductor materials containing spontaneous and/or piezoelectric polarization. Conventional heterobarrier varactors made of GaN or other III-nitride semiconductors have internal polarization charges that require additional biasing circuitry to cancel an offset voltage.
The Army Research Lab developed and patented an innovative electronic device where the N-polar and Ga-polar regions are combined into one structure with a common top and bottom electrode so that the effects of the interface charges are cancelled. This is advantageous because the circuit design is simplified and is more efficient. This eliminates the need for an additional bias to shift the CV curve so that it is symmetric about V=0. It also makes possible the generation of THz signals by tripling an input signal frequency of around 350 GHz.
Process simplification: The current-voltage curves are antisymmetric so there will be no second harmonic noise compensation required in the circuit design
High frequency capability: Generate THz signals by tripling an input signal frequency of around 350 GHz
No bias voltage necessary: The polar semiconductor stacks create opposite charge by spontaneous and/or piezoelectric polarization
US Patent 9,166,068 is available for license
Potential for collaboration with Army’s world class group of scientists