Sensitivity Improvement in GaAsSb-Based Heterojunction Backward Diodes by Optimized Doping Concentration

Abstract

An impedance-matched voltage sensitivity (β v,opt ) of 20 400 V/W at 94 GHz was achieved at zero bias and room temperature using heterojunction backward diodes that were based on a p + -GaAsSb/i-InAlAs/n-InGaAs that was lattice matched to an InP substrate. Doping concentrations in the diodes were adjusted to optimize the sensitivity and its nonlinear characteristic. The proper donor doping concentration in n-InGaAs to increase its sensitivity was determined to be 1×10 18 cm −3 . Meanwhile, the proper acceptor doping concentration in a p-GaAsSb layer was 5 × 10 18 cm −3 to achieve a large nonlinearity as a curvature coefficient (γ ) of −49.4 V −1 , which exceeded that of ideal Schottky diode. The dependence of doping concentration on noise performance was also considered. The lattice-matched GaAsSb-based backward diodes are applicable in millimeter wave detectors and mixers.Index Terms-Backward diode, GaAsSb, interband tunneling, lattice match, millimeter wave, nonlinearity, sensitivity, zero bias.

Demonstration of GaAsSb/InAs nanowire backward diodes grown using position-controlled vapor–liquid–solid method

“…Such diodes are expected to act as highsensitivity receiver diodes for signal detection in wireless communication, energy harvesters, and so on. 10,11) To fabricate high-quality NW heterostructures, two bottom-up growth methods, the vapor-liquid-solid (VLS) growth method [12][13][14][15][16][17][18][19] and selective-area epitaxial growth (SAG) method, have been intensively studied. [20][21][22] In VLS growth of III-V semiconductors, Au is commonly used as an ideal catalyst, because Au has relatively low eutectic temperatures with group-III metals and low solubilities in III-V semiconductors.…”

“…The absolute value was smaller than that of mesa BWDs fabricated from lattice-matched GaAsSb=InGaAs films on InP substrates. 10) This small absolute value of the nonlinearity coefficient was due to the large tunnel barriers. The device performance will be improved by forming smaller tunneling barriers by increasing the doping concentration and=or Sb content of GaAsSb.…”

III–V nanowire backward diodes with high sensitivity above 1 MV W−1 for low-power microwave energy harvesting

“…16,17) Sensitivity of the NW BWDs was improved by modifying growth conditions of the NWs and the device structures. 18,19) However, one drawback of BWDs is on their dynamic range, which was limited to below 0 dBm due to their low forward breakdown voltage (FBV) of around 0.4 V. 20) The adoption of extended anode structure in GaAsSb NWs 21,22) shows a significant improvement of the FBV, which signifies that the NW structure contributes not only on improving the sensitivity via the reduction of C j , but also in increasing the dynamic range of microwave power detection.…”

Type-II p-GaAsSb/n-InAs multi-nanowire backward diodes for rectification of low-power RF signals under a zero-bias condition

“…12,13) Hence, we developed GaAsSb-based BWDs with a type-II p-GaAs 0.51 Sb 0.49 /n-InGaAs heterojunction that is latticematched to an InP substrate. 14,15) The GaAsSb materials, which incorporate arsenide, seem to be more stable than GaSb. We achieved a nanowire (NW) growth technique 16) for forming a small junction area of approximately 0.2 μm without an etching process.…”

“…The γ has a theoretical limit of q/kT when SBDs are used. 27) On the contrary, BWDs exceeded the γ limitation over the SBDs, 11,15) which improves the η PC . A single-NW BWD displayed a high junction resistance R j of 9.5 GΩ, which was calculated from ∂v/∂i at zero-bias in Fig.…”