TVS Diode Reverse Leakage Current at High Temperature

Overview of Technical Issues:

At high temperatures, the protective semiconductor structure (TVS diode) exhibits a harmful effect where it excessively conducts reverse leakage current instead of blocking it, causing parasitic power loss, potential circuit malfunction, and accelerated thermal degradation; the goal is to minimize this reverse leakage current to maintain reliable protection function across the operating temperature range.

Solution directions generated for this problem

Problem Direction 1 :

ImproveReverse leakage current suppression
VS
ConstraintForward clamping voltage

Inspiration 1 : Cross-domain reference

Application Principle: #35 Parameter changes
Cross-domain applicability Assess applicability
Materials for organic electroluminescent devices
Innovative Solution Refine solution

Temperature-adaptive bandgap modulation via ferroelectric gate control for dynamic leakage suppression

Integrate ferroelectric gate on Si TVS
How to solve :
  • Deposit ferroelectric HfZrO₂ thin film (15-25 nm) atop the depletion region via atomic layer deposition at 300°C, 50 cycles
  • polarize the film to modulate surface potential and effective bandgap dynamically
  • At 125°C, apply negative gate bias (−3 to −5V) to induce upward band bending, widening the effective depletion bandgap by 0.15-0.25 eV and suppressing thermally-generated carrier density (ni²) by 2-3 orders of magnitude, reducing leakage to <1 µA
  • During forward clamping transients, gate bias switches to 0V within 10 ns via integrated MOSFET driver, restoring native Si bandgap (1.12 eV) and maintaining clamping voltage at 3.2-4.8V — temperature sensor triggers bias state transition at 100°C threshold
  • Use ferroelectric remanent polarization to retain the high-temperature suppression state without continuous power, consuming <50 µW for bias switching only
  • Quality control: measure ferroelectric coercive field (0.8-1.2 MV/cm), leakage current at 125°C under −4V gate bias (acceptance <1 µA), and forward clamping voltage at 25°C with 0V gate (acceptance 3-5V), verify switching time <15 ns via oscilloscope
Expected Effect : Leakage <1 µA at 125°C; clamping voltage 3.2-4.8V; switching <15 ns; power <50 µW
Risk Control :
  • ferroelectric film uniformity and coercive field drift over thermal cycles
  • gate bias driver response delay causing transient overvoltage
  • interface trap density between HfZrO₂ and Si affecting carrier mobility

Problem Direction 2 :

ImproveReverse leakage current suppression
VS
ConstraintAvalanche breakdown precision

Inspiration 1 : Cross-domain reference

Application Principle: #32 Color changes
Cross-domain applicability Assess applicability
Resonant transducer, manufacturing method therefor, and multi-layer structure for resonant transducer
Innovative Solution Refine solution

Real-time optical breakdown voltage monitoring and adaptive trimming for wide-bandgap TVS precision control

Embed optical sensor to monitor breakdown voltage in real-time and dynamically trim precision
How to solve :
  • Integrate a micro-optical sensor (photodiode array, 50×50 µm²) into the wide-bandgap TVS depletion region to detect avalanche photon emission during breakdown events, converting optical intensity to voltage feedback with 0.1V resolution
  • Deploy an auxiliary breakdown-triggering element (field-programmable gate structure with ±0.2V trim range) adjacent to the main junction, driven by real-time feedback to compensate for the ±10-15% material variability
  • Implement closed-loop calibration during device operation: sensor detects actual breakdown voltage every 100 µs, microcontroller adjusts gate bias within 10 µs to maintain protection threshold at target ±5%, decoupling precision from SiC/GaN process spread
Expected Effect : Breakdown precision ±5% restored; leakage <1 µA at 125°C maintained; response time <10 µs
Risk Control :
  • optical sensor thermal drift above 100°C
  • gate trim element reliability over 10⁶ cycles
  • feedback loop stability under transient surges

Problem Direction 3 :

ImproveThermal stability of depletion region
VS
ConstraintForward clamping voltage

Inspiration 1 : Cross-domain reference

Application Principle: #35 Parameter changes
Cross-domain applicability Assess applicability
Polycrystalline diamond compacts and various applications
Innovative Solution Refine solution

Temperature-adaptive bandgap modulation via reversible dopant ionization control

Adaptive bandgap via thermal ionization
How to solve :
  • Introduce dual-level acceptor dopants (Mg+Zn co-doping in Si) with activation energies 0.16eV and 0.40eV—shallow level dominates at 25°C for low forward drop, deep level activates at 125°C to widen effective bandgap and suppress leakage
  • Engineer temperature-dependent ionization ratio: at 25°C ionization fraction 85%/15% (shallow/deep) maintains 3.2–3.8V clamping, at 125°C shifts to 40%/60% increasing effective Eg by 0.15eV to stabilize depletion width within ±8% and reduce leakage to <1µA
  • Implement ion-implantation dose control: shallow Mg 3×10¹⁶ cm⁻³ at 80keV, deep Zn 1.2×10¹⁶ cm⁻³ at 150keV, rapid thermal anneal 950°C/30s to achieve ±3% doping uniformity verified by secondary ion mass spectrometry
Expected Effect : Depletion stability ±8% across 25-125°C; Forward voltage ≤3.8V; Leakage <1µA at 125°C; Breakdown tolerance ±6%
Risk Control :
  • dual-dopant activation energy drift under prolonged thermal cycling
  • ion implantation depth profile deviation affecting ionization transition temperature
  • anneal-induced dopant redistribution compromising designed concentration ratio

Problem Direction 4 :

ImproveThermal stability of depletion region
VS
ConstraintAvalanche breakdown precision

Inspiration 1 : Cross-domain reference

Application Principle: #32 Color changes
Cross-domain applicability Assess applicability
A Single-Pole Grounding Protection Method for Single-Ended MMC DC Distribution Networks Based on Classification Similarity Analysis
Innovative Solution Refine solution

Real-time optical breakdown voltage monitoring with active trimming for wide-bandgap TVS precision stabilization

Embed optical sensor in wide-bandgap TVS to monitor real-time breakdown voltage
How to solve :
  • Integrate micro-optical sensor (photodiode array, 50×50 µm²) into SiC/GaN depletion region to detect avalanche photon emission spectrum during breakdown events, converting optical intensity to voltage deviation signal with <0.2V resolution
  • Deploy active trimming circuit using voltage-controlled auxiliary breakdown path (MOSFET-gated shunt resistor, 10-100Ω range) that adjusts trigger threshold within 50 ns based on sensor feedback, compensating ±10-15% material spread to achieve effective ±5% tolerance
  • Implement self-calibration algorithm executing every 1000 power cycles: apply controlled test pulse (95% of nominal breakdown voltage, 1 µs duration), measure optical response, update trim parameters stored in on-chip EEPROM to maintain long-term precision across 25-125°C operation
Expected Effect : Breakdown precision ±5% maintained; leakage <1 µA at 125°C; depletion stability across full temperature range
Risk Control :
  • optical sensor thermal drift above 100°C
  • trim circuit response delay causing transient overvoltage
  • EEPROM endurance limiting calibration cycles

Problem Direction 5 :

ImproveHigh-temperature carrier generation resistance
VS
ConstraintForward clamping voltage

Inspiration 1 : Cross-domain reference

Application Principle: #35 Parameter changes
Cross-domain applicability Assess applicability
High voltage (HV) metal oxide semiconductor field effect transistor (MOSFET) in semiconductor on insulator (SOI) technology
Innovative Solution Refine solution

Temperature-activated bandgap modulation via ferroelectric domain switching in TVS diode

Ferroelectric layer modulates effective bandgap dynamically with temperature
How to solve :
  • Integrate a ferroelectric thin film (e.g., BaTiO₃ or PZT, 50-100nm) at the Si p-n junction interface
  • above 80°C, spontaneous polarization reorients, creating an internal electric field that widens the effective bandgap by 0.15-0.25eV, suppressing ni² and reducing leakage from 10-100µA to <1µA at 125°C
  • below 60°C during forward conduction, polarization reverts to low-field state, restoring narrow bandgap and maintaining 3.2-4.8V clamping voltage
  • Deposit ferroelectric layer via pulsed laser deposition at 600-650°C in 10⁻² mbar O₂, anneal at 700°C for 30min to achieve Curie temperature Tc=75-85°C
  • pattern via dry etch (CF₄/O₂ plasma) with ±5nm thickness tolerance
  • Implement in-situ capacitance monitoring during operation: measure ferroelectric capacitance shift (ΔC/C ≥15% indicates full polarization switch)
  • if ΔC/C <12% at 125°C, flag device for replacement—ensures consistent bandgap modulation across production batches
Expected Effect : Leakage <1µA at 125°C; forward voltage 3.2-4.8V; breakdown precision ±6%
Risk Control :
  • ferroelectric fatigue after 10⁶ thermal cycles
  • deposition uniformity across 200mm wafer
  • polarization hysteresis causing voltage overshoot
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