Infineon is the world&#;s first Silicon Carbide (SiC) discrete power supplier. Long market presence and experience enable Infineon to deliver highly reliable, industry-leading SiC performance. The differences in material properties between Silicon Carbide and Silicon limit the fabrication of practical Silicon unipolar diodes (Schottky diodes) to a range up to 100 V&#;150 V, with relatively high on-state resistance and leakage current. In SiC material Schottky diodes can reach a much higher breakdown voltage. The Infineon portfolio of Silicon Carbide (SiC) products covers 600 V and 650 V to V Schottky diodes.
Hornby Electronic contains other products and information you need, so please check it out.
In this work, a 3D thermal analysis of the planar Schottky diode chips with single and double-row anode arrangements is first systematically presented. The steady-state thermal characteristics of the chips are analyzed by solving the heat equation in the 3D calculation domain. This paper aims to gain insight into the internal heat distribution of Schottky diodes with different anode arrangements during operation. The heat distribution of Schottky diodes with single and double-row anode arrangements under the same excitation is studied, as well as the temperature distribution of Schottky diode chips with different substrate materials, including sapphire, silicon (Si), silicon carbide (SiC), and diamond. The effects of substrate geometrical parameters and anode spacing on the thermal characteristics of Schottky diode chips are systematically analyzed.
Accurately predicting the anode junction temperature [ 15 ] and understanding the heat flow law inside the GaN SBD chips is the basis for developing effective thermal management strategies [ 16 ]. The heat transport process in GaN SBD is dominated by thermal conduction, with heat generated at the Schottky junction interface and transported through the GaN epitaxial layer, the GaN buffer layer, the substrate, and, finally, dissipated to the external environment [ 17 ]. In recent years, the thermal management of Schottky diode-based multipliers has been investigated in many research works. Aik Yean Tang et al. [ 18 ] presented a self-consistent electro&#;thermal model for multi-anode Schottky diode multiplier circuits. The thermal model is developed for an n-anode multiplier via a thermal resistance matrix approach. The model could predict the hot spot temperature in the frequency multiplier chip. Carlos et al. [ 19 ] presented the thermal analysis of different Schottky diode frequency doubler chip layouts. Cui et al. [ 20 ] presented the temperature distribution of the diode at dissipated powers, studied through electromagnetic heating multi-physics coupled with heat transfer in solids and electric currents. Song et al. [ 21 ] presented thermal characterization results of GaN Schottky diodes in the frequency multipliers with flip-chip configuration. These reports have provided valuable insights for our work with GaN SBD. However, reports on thermal analysis of the SBD chips with double-row anode arrangement by coupling Joule heat with solid heat transfer are limited.
Terahertz waves have great potential applications, such as earth atmospheric remote sensing, biomedicine, high-speed communication, spectroscopic, and imaging techniques [ 1 5 ]. Terahertz sources are the key component for generating terahertz waves, which are essential for the development of terahertz electronic systems. At present, the frequency multiplier based on gallium nitride (GaN) planar Schottky barrier diode (SBD) has been developing rapidly and gaining great attention due to its high breakdown voltage, high electron mobility, and high thermal stability [ 6 7 ]. The current mainstream method to obtain a high output power is to withstand sufficient input power [ 8 ]. However, excessive input power generates an amount of heat that causes the temperature inside the diode to rise rapidly, and GaN SBD faces challenges related to the self-heating effect, which can degrade device performance and long-term reliability [ 9 ]. Therefore, chip thermal management has become an important aspect in the design of Schottky diode-based circuits for high-power applications [ 10 14 ].
The 3D model of multi-anode planar Schottky diode chips is illustrated in Figure 1 . As shown in Figure 1 a,b, one chip comprises six anodes with single-row anode arrangement. The other comprises 12 anodes in an anti-series arrangement with double-row anode arrangement. Figure 1 c shows the cross-view of the single-anode planar Schottky diode. The diode contains metal electrodes, a low-doped n-GaN layer, a high-doped n-GaN layer, a GaN buffer layer, and a substrate. Because the temperature distribution of the chip is affected by the area of the anode junction, the area of each anode junction on the single-row anode arrangement chip is 18.1 μm. While the area of each anode junction on the double-row anode arrangement chip is 9.05 μm, apart from this, their geometric and material parameters are the same.
amb), while other surfaces are assumed as adiabatic, i.e., the thermal radiation and the heat convection are ignored. For simplicity, the thermal properties of the epitaxial layer, the highly doped layer, and the buffer layer are assumed to be the same. In the simulation, the anode consists only of gold, although, in fact, the anode is composed of titanium (Ti), aluminum (Al), nickel (Ni), and gold (Au), as this has little effect on the thermal simulation results. The temperature-dependent thermal properties of semiconductors are considered.Q = &#; &#; · k T &#; T
(1)
Contact us to discuss your requirements of Custom Schottky diode thermal management Factory. Our experienced sales team can help you identify the options that best suit your needs.
T
is temperature,k
(T
) is the temperature-dependent thermal conductivity, andQ
is the heat generation rate per unit volume.In the simulation, the temperature distribution of the Schottky diode chip is analyzed by coupling Joule heating with solid heat transfer because the heat comes from the Joule heat generated by the current flowing through the Schottky diode in practice. In a frequency multiplier, the chip is connected to the waveguide block by two beam leads. So, the two facets of the substrate facing the waveguide are set as the ambient temperature (T), while other surfaces are assumed as adiabatic, i.e., the thermal radiation and the heat convection are ignored. For simplicity, the thermal properties of the epitaxial layer, the highly doped layer, and the buffer layer are assumed to be the same. In the simulation, the anode consists only of gold, although, in fact, the anode is composed of titanium (Ti), aluminum (Al), nickel (Ni), and gold (Au), as this has little effect on the thermal simulation results. The temperature-dependent thermal properties of semiconductors are considered. Table 1 lists the thermal conductivities and electric conductivities of the materials used in the simulations [ 22 23 ]. All calculations in this work are based on the finite-element method (FEM) as implemented in COMSOL multiphysics. Upon setting up the proper simulation boundaries and material properties, the temperature can be derived from the following formula (1):whereis temperature,) is the temperature-dependent thermal conductivity, andis the heat generation rate per unit volume.
diss generated by the Schottky diode during operation can be calculated by Joule&#;s law. diss) to the anode junction. It can be seen that the overall temperature of the device calculated by coupling Joule heat with solid heat transfer is higher than that using only solid heat transfer. In theory, the coupling method of Joule heat and solid heat transfer is closer to the actual working state of the device than the method of only using solid heat transfer.When the diodes work, the heat comes from the Joule heat generated by the current flowing through the epitaxial layer. So, the temperature distribution of the Schottky diode chip is analyzed by coupling Joule heating with solid heat transfer. The current flowing through the Schottky diode can be obtained by surface integration of the current density on the cathode pad, and the thermal dissipation power Pgenerated by the Schottky diode during operation can be calculated by Joule&#;s law. Figure 2 shows the simulation results of the same device by using Joule heat and applying a heat source (P) to the anode junction. It can be seen that the overall temperature of the device calculated by coupling Joule heat with solid heat transfer is higher than that using only solid heat transfer. In theory, the coupling method of Joule heat and solid heat transfer is closer to the actual working state of the device than the method of only using solid heat transfer.
amb) is set as 293.15 K, the same voltage source is applied to the central pad of the two chips, respectively. The simulated overall temperature distribution of the chip with single-row arrangement is shown inWhen the ambient temperature (T) is set as 293.15 K, the same voltage source is applied to the central pad of the two chips, respectively. The simulated overall temperature distribution of the chip with single-row arrangement is shown in Figure 3 a. The simulated overall temperature distribution of the chip with double-row anode arrangement is shown in Figure 3 b. When the Schottky diode is working, the current flowing through the diode generates a lot of heat at the anode junction, and the heat is transferred to the entire chip through thermal conduction. The maximum temperature of the chip with single-row anode arrangement is 31 K higher than that of the chip with double-row anode arrangement. In the chip, the anode junction near the center welded plate has the highest temperature. Figure 3 c shows the heat flux around the anode. It can be found that heat flows around the anode junction, where the temperature is highest. So, the temperature distribution at the anode junctions of the chip was studied.
Want more information on Custom Schottky diode thermal management Exporter? Feel free to contact us.