4H-SiC Schottky Diode DLTS simulation

sicex12.in : 4H-SiC Schottky Diode DLTS simulation

Requires: S-Pisces
Minimum Version Atlas 5.28.1.R

Deep-level transient spectroscopy (DLTS) is an experimental tool for studying electrically active defects (known as charge carrier traps) in semiconductors. DLTS establishes fundamental defect parameters and measures their concentration in the material.

DLTS investigates defects present in a space charge (depletion) region of a simple electronic device. The most commonly used are Schottky diodes or p-n junctions. In the measurement process the steady-state diode reverse polarization voltage is disturbed by a voltage pulse. This voltage pulse reduces the electric field in the space charge region and allows free carriers from the semiconductor bulk to penetrate this region and recharge the defects causing their non-equilibrium charge state. After the pulse, when the voltage returns to its steady-state value, the defects start to emit trapped carriers due to the thermal emission process. The technique observes the device space charge region capacitance where the defect charge state recovery causes the capacitance transient. The voltage pulse followed by the defect charge state recovery are cycled allowing an application of different signal processing methods for defect recharging process analysis. The emission rate is temperature dependent and characteristic for each type of defect. From the temperature dependence of the emission rate the activation energy of a deep level can be deduced.

In this example we demonstrate how to simulate capacitance variation versus time and temperature on a 4H-SiC Schottky barrier Diode (SBD). To do so we used the loop statement combined with the set statement to run multiple simulations at different temperature and save files accordingly.

From the simulation results we also show how to simulate temperature dependence of the capacitance difference (extracted at 2 different simulation time i.e 20ms in that case). In this input deck carrier capture cross section SIGN and SIGP were set to 5.6e-15 but could easily be changed to verify emission rate is temperature dependent

Simulation results agree very well with DLTS theory.

To load and run this example, select the Load button in DeckBuild > Examples. This will copy the input file and any support files to your current working directory. Select the Run button in DeckBuild to execute the example.