13-10-2010, 12:32 PM
POWER SYSTEM & DRIVES.ppt (Size: 1.59 MB / Downloads: 85)
This article is presented by:
DHARAM VIR
Master of Technology in Electrical Engineering
YMCA INSTITUTE OF ENGINEERING, FARIDABAD
JULY 2009
Analytical Analysis of Double Implanted MOSFET for High Breakdown & Low Power Dissipation using Graded Profile on 6H-SiC Wafer
Objectives of Thesis:
The main objectives of this work were as follows:
Analysis of Double Implanted MOSFET on 6H SiC wafer using uniform doping profile.
Determination of optimum breakdown & power dissipation using uniform on doping profile.
Determination of optimum breakdown & power dissipation using linearly graded profile.
Comparison between uniform and graded profile.
Calculation of percentage power save for Graded and uniform.
All the calculations and graph are plotted in MAT LAB 7.0.
The present work aims at the design of high breakdown voltage 8kv 6H-SiC Double implanted metal-oxide semiconductor field –effect transistor (DIMOSFET) with uniformly and linearly grades doping profile of drift region.In linearly graded doping profile, it is found that the height of drift region (h) decreases (148.17 um to 119.61), which reduces the specific on resistance Ron.sp. Here Ron,sp (specific on resistance) equal to Rd (specific on resistance of the drift region) for high breakdown voltages. And the power dissipation (Pd) with 8kv breakdown voltages (Vb) decreases to the value of 29.56W from 43.88W at a fixed forward current density (Jf=1000A/cm2) and effective doping level (Nd=3.91x10 14cm-3).The percentage power saved in linearly graded doping profile is about 32.64% as compared to the uniformly doped profile, but it decreases with further increase in the effective doping level
Silicon Carbide Power MOSFETs
Power switching devices are reaching fundamental limits imposed by the low breakdown field of silicon, and substantial improvements can only be achieved by using a semiconductor with a higher breakdown field. In this project, Analytical analysis of 6H Double Implanted MOSFET for high breakdown & low power dissipation using graded profile.
Why Silicon Carbide is Used?
Silicon Carbide has been recently given the intention as a potential material for high power and high frequency applications. It belongs to the class of semiconductors known as wide bandgap semiconductor.
Properties such as large breakdown electric field, large saturated electronic drift velocity, wide bandgap, small dielectric constant, reasonably high electron mobility and high thermal conductivity will make silicon carbide an attractive semiconductor for fabricating power devices with reduced power losses and die sizes.
The high breakdown fields in Silicon Carbide allow for drift regions that are eight to ten times thinner than silicon high voltage devices. This makes SiC power devices fit for operation in kilovolts and beyond and also improves the current handling capability of power devices.