Remote Gate-Controlled Negative Transconductance in Gated MIS Tunnel Diode

Abstract

The transfer characteristics of a metal-insulatorsemiconductor (MIS) tunnel diode (TD) controlled by a separated MIS TD as gate were investigated. Negative transconductance (NT) exists around the flat-band region in the transfer curve even though the separation between the gate and the MIS TD is large (up to several tens of micrometers). We called it remote gate-controlled NT (RG-NT). With the aid of the Technology Computer Aided Design simulation, the turn around behaviors of the lateral electric field and electron concentration around the flat-band region explain well the RG-NT phenomenon. The peak-to-valley current ratio (PVCR) of the RG-NT increases with the tunnel oxide thickness. The maximum PVCR obtained in this work is 1.3 × 10 6 while the oxide thickness is 3.3 nm.Index Terms-Metal-insulator-semiconductor (MIS) tunnel diode (TD), negative transconductance (NT), peak-to-valley current ratio (PVCR), remote gate-controlled, Schottky barrier modulation.

Negative transconductance effect in p-GaN gate AlGaN/GaN HEMTs by traps in unintentionally doped GaN buffer layer*

“…Earlier researches have revealed the mechanisms of negative transconductance, such as the increase of the intrinsic base resistance in AlGaAs/GaAs HBTs, [15] the electric field distribution in the channel in HFETs, [16] surface-roughness in MOSFETs, [17] and electrode space in MIS tunnel diode. [18] And more recently, negative transconductance were found in MoS 2 /Wse 2 heterojunction transistor. [19] However, few studies reported that the negative transconductance is attributed to the traps in UID buffer layer in p-GaN gate AlGaN/GaN HEMT.…”

Modulation of Minority Carriers in the C-V Characteristics of MIS Tunneling Diode by Surrounding MOS Capacitor

“…As can be seen from the band diagram of MIS TD, the higher the minority carrier concentration at substrate surface, the larger the voltage across the oxide, and the lower the effective Schottky barrier height, i.e., φ h * < φ h0 *. Therefore, the current of the MIS TD with surrounding MOS capacitor is larger according to equations [1] and [2]. The other evidence for minority carrier modulated by outer surrounding MOS capacitor is the outer gate bias (Vg) influence on the C-V and I-V characteristics of inner MIS TD (I TD -V TD and C TD -V TD ), as shown in Fig.…”

“…MOSCAP [1] J h = A*P t T 2 exp(-qφ h */kT), for MIS TD with surr. MOSCAP [2] where φ h0 * and φ h * are the effective Schottky barrier heights for holes tunneling from metal to substrate. As can be seen from the band diagram of MIS TD, the higher the minority carrier concentration at substrate surface, the larger the voltage across the oxide, and the lower the effective Schottky barrier height, i.e., φ h * < φ h0 *.…”

Current Coupling Effect in MIS Tunnel Diode with Coupled Open-Gated MIS Structure

“…And, it was believed that the saturation current of MIS TD increases with the peripheral lateral flux of minority carriers if the majority carriers would encounter the effective Schottky barrier as tunneling through the oxide to the semiconductor (2). The mechanism is that the saturation current of MIS TD, I sat , exponentially increases with the decrease of effective Schottky barrier height,  h * , and the effective Schottky barrier height decreases with the increase of lateral flux of minority carriers, F e , due to the increase of oxide voltage, V ox , i.e., (3) the lateral flux of electrons and the oxide thickness, d ox . Note that V ox increases with F e since the oxide voltage increases with larger electron concentration at the substrate surface.…”