Thin-barrier gated-edge termination AlGaN/GaN Schottky barrier diode with low reverse leakage and high turn-on uniformity

Abstract

In this study, novel AlGaN/GaN Schottky barrier diodes (SBDs) are fabricated with thin-barrier (5 nm) AlGaN/GaN heterostructures, featuring recess-free technology, eliminating bombardment plasma damage, and leading to high device uniformity. Combining a gated-edge termination (GET) design and assistance with high-quality low-pressure chemical vapor deposition SiN x , a low reverse leakage current (∼10 nA mm −1 @−600 V) and a high reverse breakdown voltage of over 1.78 kV (@1 µA mm −1 ) are obtained. At the same time, we achieve a low turn-on voltage of 0.57 V and a low differential on-state resistance R on,sp of 1.49 mΩ cm 2 for thin-barrier GET SBDs with an anode-to-cathode distance (L AC ) of 15 µm, yielding a Baliga's figure of merit of 2120 MW cm −2 . Moreover, this proposed diode process flow is compatible with AlGaN/GaN high-electron-mobility transistors, which is promising for its integration in the smart GaN platform.

The Influence of Design on Electrical Performance of AlGaN/GaN Lateral Schottky Barrier Diodes for Energy-Efficient Power Applications

“…As a result of the investigation carried out, an optimal set of diode construction features was identified, as well as general dependences between design features and electrical parameters. The obtained dependences partially agree with the results presented in other works, in which the diodes were manufactured on CMOS fabs [15,16] and RF fabs [18][19][20][21][22][23][24][25][26][27][28]. Particularly, a decrease in reverse currents and an increase in forward currents with an increase in the depth of the subanode recess on structures with Ni SC was observed, as was the case in [22].…”

“…Many results of design and production of GaN Schottky barrier diodes (SBDs) have been presented [15][16][17][18][19][20][21][22][23][24][25][26][27][28]. Some research has been focused on CMOS fabs [15][16][17] and other research has focused on RF fabs [18][19][20][21][22][23][24][25][26][27][28].…”

“…Many results of design and production of GaN Schottky barrier diodes (SBDs) have been presented [15][16][17][18][19][20][21][22][23][24][25][26][27][28]. Some research has been focused on CMOS fabs [15][16][17] and other research has focused on RF fabs [18][19][20][21][22][23][24][25][26][27][28]. To date, quite a lot of design features have been reported regarding SBDs, and most of reported results have used field plates for efficient electric field redistribution between anode and cathode, and increasing the diode's breakdown voltage (V BR ) [16]; increasing anode-to-cathode distance leads to an increase in the diode's resistance in the ON-state (R ON ) and V BR [29].…”

Investigation on Dynamic Characteristics of AlGaN/GaN Lateral Schottky Barrier Diode

“…V stress applied to the SBD yielded negative charges in the buffer and positive charges (or reduction of electrons) in the 2DEG. As shown in Figure 8, the opposite doping polarities in the UID and C-doped buffer layers could result in a p-n junction at the UID/buffer interface, which becomes reversely biased under V stress with the depletion region extending into the two layers and excessive ionization of both donor and acceptor traps [13]. Moreover, the ionization of the acceptor traps in the buffer layer can result in negative space charges, leading to a significant reduction of the 2DEG sheet charge density and forward current.…”

“…In our previous work, a recess-free AlGaN/GaN heterojunction Schottky diode structure with a thin barrier was proposed, with a two dimensional electron gas (2DEG) being effectively preserved by silicon nitride (SiN x ) passivation grown by low pressure chemical vapor deposition (LPCVD) [12,13]. We demonstrated the static characteristics of the SBD in our previous work, but dynamic characterization and quantitative modeling are still missing.…”