Fabrication and characterization of pre-aligned gallium nitride nanowire field-effect transistors

Abstract

We report on the fabrication of gallium nitride (GaN) nanowire field-effect transistors (FETs) with both bottom-gate and top-gate structures, with very high yield using a unique pre-alignment process. The catalyst positions were chosen to be aligned with the source/drain position, and Ni catalysts with a diameter of 200 nm were deposited selectively at these pre-determined positions. Electrostatic analysis was performed for the bottom-gate devices to estimate the nanowire’s electrical characteristics. Comparison of the bottom-gate and the top-gate structures indicated that better performance, in terms of saturation and breakdown characteristics, can be obtained using the top-gate structure. For the top-gate nanowire FETs, temperature-dependent characteristics were investigated up to the current saturation regime, and memory effects were observed at room temperature.

A Semi-analytical Model for Depletion-mode N-type Nanowire Field-effect Transistor (NWFET) with Top-gate Structure

“…The nanowire circuits defined by assembly of the nanowire devices such as the semiconducting nanowire field-effect transistor (NWFETs) have been demonstrated already by the bottom-up paradigm [1][2][3][4][5]. Especially, NWFETs among the nanowire devices have demonstrated promising field-effect transistor (FET) characteristics in top-gate [6][7][8][9][10], bottom-gate [9][10][11][12][13], and surround-gate [14] FET geometries. Most of NWFETS have operated in accumulation or depletion mode [6][7][8][9][10][11].…”

“…Especially, NWFETs among the nanowire devices have demonstrated promising field-effect transistor (FET) characteristics in top-gate [6][7][8][9][10], bottom-gate [9][10][11][12][13], and surround-gate [14] FET geometries. Most of NWFETS have operated in accumulation or depletion mode [6][7][8][9][10][11]. The NWFETs have generally a metalsemiconductor-metal (MSM) structure [1][2][3][4][5][6][7][8][9][10][11][12][13][14], and the metal-semiconductor (MS) contacts in the NWFET can classify with Schottky contact and ohmic contact [15].…”

“…Most of NWFETS have operated in accumulation or depletion mode [6][7][8][9][10][11]. The NWFETs have generally a metalsemiconductor-metal (MSM) structure [1][2][3][4][5][6][7][8][9][10][11][12][13][14], and the metal-semiconductor (MS) contacts in the NWFET can classify with Schottky contact and ohmic contact [15]. The NWFETs mostly composed of two Schottky contacts connected back to back, in series with a semiconducting nanowire operating as the intrinsic NWFET [15,16].…”

“…To design and simulate the nanowire circuits, a few compact models of depletion-mode NWFETs with bottom-gate structure have been reported so far [9,[15][16][17][18]. Recently, we have developed a depletion-mode NWFET model including the surface depletion effect and the accumulated charges [17].…”

Fabrication of High-Density GaN Nanowires through Ammoniating Ga2O3/Nb Films

“…Progress has been made in the synthesis of ordered GaN nanowires with controlled cross-section, length, and diameter [5]. Applications of GaN nanowires for single nanowire laser [6] and individual device fabrication [7][8][9][10][11] have also been demonstrated. In recent years, our group develops a novel method for synthesizing one-dimensional GaN materials through ammoniating Ga 2 O 3 films [12], Ga 2 O 3 /Al 2 O 3 films [13] and Ga 2 O 3 /SiC films [14] and Ga 2 O 3 /ZnO films [15], Ga 2 O 3 /MgO films [16], which are deposited by rf magnetron sputtering.…”