Au-Free AlGaN/GaN Power Diode on 8-in Si Substrate With Gated Edge Termination

2014 IEEE 26th International Symposium on Power Semiconductor Devices &Amp; IC's (ISPSD)

Hove

et al. 2014

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Abstract-In this work we show the impact of surface cleaning on the dynamic characteristics of Au-free AlGaN/GaN Gated Edge Termination Schottky Barrier Diodes (GET-SBDs). It is demonstrated that the current dispersion (measured in pulsed regime) can be reduced by introducing a N 2 plasma cleaning step in the anode metal deposition chamber. Moreover, diodes treated with N 2 plasma show lower current drop after reverse voltage stress (with a relative forward voltage increase of 2% after stress) than diodes without clean or with Atomic Layer Etching (ALE) clean (20% and 37% relative forward voltage increase, respectively).

“…The processing continued with the Au-free cathodes (a Ti/Al/Ti/TiN-based stack, annealed at 550 ºC) and Au-free backend [1].…”

Section: Device Fabricationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Improvement of the dynamic characteristics of Au-free AlGaN/GaN Schottky Diodes on 200 mm Si wafers by surface treatments

2014 IEEE 26th International Symposium on Power Semiconductor Devices &Amp; IC's (ISPSD)

Hove

et al. 2014

Self Cite

“…AlGaN/GaN Schottky Barrier Diodes (SBDs) are promising devices for high-power, high-temperature, and high-frequency applications due to their superior material properties including high channel charge density as well as large breakdown field strength [1,2]. To make the technology cost-effective and compete with Si-based power devices, efforts have been done to fabricate high-performance AlGaN/GaN SBDs on large diameter (200 mm) GaN-on-Si wafers with Au-free CMOS-compatible process flow [1,2].…”

Section: Introductionmentioning

confidence: 99%

Physical origin of current collapse in Au-free AlGaN/GaN Schottky Barrier Diodes

Stoffels

Microelectronics Reliability

et al. 2014

Dynamic characterization (Pulsed I-V) on Au-free AlGaN/GaN Schottky Barrier Diodes (SBDs) has been performed to evaluate the impact of negative quiescent bias on the forward characteristics. Results show an increase of on-resistance when more negative quiescent biases are applied, and a sudden current collapse phenomenon when the quiescent bias exceeds -175 V. Furthermore, the measurements show a common signature: the total current collapse is the result of the trapping phenomena occurring around the Schottky contact corner. The trap levels of 0.5 eV and 1.0 eV have been characterized from current transient spectroscopy. A TCAD model with these two trap levels as donor states at the Si3N4/AlGaN interface has been defined, to understand their role and explain the observed behavior of AlGaN/GaN SBDs from this dynamic measurement. We propose that trapping at deep energy levels (Trap1=1.0 eV), existing at the Si3N4/AlGaN interface, is responsible for the gradual current reduction observed for negative quiescent biases up to Anode-to-Cathode voltage of -175 V. The electron filling of the shallower traps with high density at energy level located 0.5 eV below the conduction band starts at higher reverse biases, resulting in a strong Fermi-level pinning, which can be the cause of sudden current collapse.

Leakage and trapping characteristics in Au‐free AlGaN/GaN Schottky barrier diodes fabricated on C‐doped buffer layers

Stoffels

Physica Status Solidi (a)

et al. 2016

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We investigate the DC and dynamic characteristics of AlGaN/GaN Schottky barrier diodes (SBDs) and the diodes with a gated edge termination (GET‐SBD) fabricated on unintentional doped (UID) and carbon‐doped AlGaN buffers. The off‐state characteristics of diodes fabricated on UID buffer are dominated by buffer leakage and buffer breakdown voltage (BV) at higher reverse voltage (VR larger than 300 V). An improvement in diode leakage and BV can be obtained by fabricating the GET‐SBDs on C‐doped buffers. A pronounced RON degradation of the AlGaN/GaN SBDs and GET‐SBDs on carbon‐doped buffers was observed by dynamic pulsed I−V characterization. This dynamic RON degradation causes a clear forward current reduction for the AlGaN/GaN GET‐SBDs. From combined off‐state stress and current transient measurements on AlGaN/GaN SBDs, the collapsed current is recoverable and the RON degradation is due to a temporary trapping mechanism occurring in the buffer. A distinct trap level of 0.57 eV from trap spectra has been extracted for the diode fabricated on C‐doped buffer, and the value was implemented in a TCAD simulator. The simulated results confirm a bulk trapping in the buffer layer for the SBD and show an additional trapping region in the GET‐SBD architecture.