Trapping effects in Al2O3/AlGaN/GaN metal-oxide-semiconductor heterostructure field-effect transistor investigated by temperature dependent conductance measurements

Abstract

Frequency dependent conductance measurements at varied temperature between 25 and 260 °C were performed to analyze trapping effects in the Al2O3/AlGaN/GaN metal-oxide-semiconductor heterostructure field-effect transistors. The trap states with a time constant τT,f≅(0.1–1) μs (fast) and τT,s=10 ms (slow) were identified. The conductance measurements at increased temperatures made it possible to evaluate the fast trap states in about a four times broader energy range than that from room temperature measurement. The density of the fast traps decreased from 1.4×1012 cm−2 eV−1 at an energy of 0.27 eV to about 3×1011 cm−2 eV−1 at ET=0.6 eV. The density of the slow traps was significantly higher than that of the fast traps, and it increased with increased temperature from about 3×1012 cm−2 eV−1 at 25–35 °C to 8×1013 cm−2 eV−1 at 260 °C.

Current transport mechanisms and trap state investigations in (Ni/Au)–AlN/GaN Schottky barrier diodes

“…Kordoš et al [20] investigated the trapping effects in an Al 2 O 3 / AlGaN/GaN metal-oxide-semiconductor heterostructure fieldeffect transistor by temperature dependent conductance measurements. They identified two dominant trap states time constant as 1 ls and 10 ms and trap state density of the order of 10 12 eV À1 cm À2 .…”

“…The method described by Schroder for MOS capacitor analysis, which was adapted for the interface trap characterization of Al 0.15-Ga 0.85 N/GaN HFET structures by Miller et al [15], was used in the interface trap investigation in (Ni/Au)-AlN/GaN SBDs [14][15][16][17][18][19][20][21]. There are four main possibilities to consider for the spatial location of traps in (Ni/Au)-AlN/GaN SBDs: (1) the metal-semiconductor interface of the Schottky contact, (2) the bulk of the barrier layer, (3) the interface between the barrier layer and the channel, and (4) the bulk of the channel layer [15,17,18,20]. It is impossible to know where the traps are located a priori; all four locations must be considered.…”

Trap states in InAlN/AlN/GaN-based double-channel high electron mobility transistors

“…Frequency dependent conductance measurements have been widely implemented to analyze trap states in AlGaN/ GaN HEMTs, 4,5 Al 2 O 3 /AlGaN/GaN MOS-HFETs, 6,7 and AlN/AlGaN/GaN MIS-HFETs. 8 In the experiment, the well-established method is directly applied to investigate InAlN/AlN/GaN interface states.…”

Investigation of AlGaN/GaN HEMTs degradation with gate pulse stressing at cryogenic temperature

“…16 However, high frequency C-V or conductance measurement has some limitations since the emission time constants of the trap states were over a broad range, the static test of temperature-induced instability of the threshold voltage is more appropriate. 17,18 Because of the ability of GaN material to withstand high temperatures, extensive reliability studies are present in literature for high temperature applications. 19 With the extensive applications of power devices at very low temperature, 20,21 such as deep space exploration et al, it is of great important also to investigate low temperature reliability behavior of GaN based HEMT.…”