Slide 1Team MembersTeam ResponsibilitiesGroup MotivationOverviewKey SpecificationsSystem ComponentsPrototype LayoutDesign EquationsSi & SiC Plot of Resistance vs. TemperatureController Board DevelopmentToleranceOperating VoltageCost AnalysisConclusions/Future WorkSlide 16Silicon CarbideTemperature Sensorfor Harsh EnvironmentsChris Rice Jason WallaceMichael Jackson Jovan BjelobrkADVISORDr. Stephen Saddow“a hot project…a cool advisor”Team MembersTeam ResponsibilitiesJovan BjelobrkJason WallaceMichael JacksonChris RiceProject Planning/CoordinationSensor DesignFabricationSensor DesignDocumentationSoftware/Web DesignDocumentationDevice Controller DesignGroup MotivationResearch of New SystemResearch of New Materials in Semiconductor TechnologyWithin our Realm of CapabilityOverviewNo reliable way to detect temperature changes in extreme environments using typical semiconductor material (Si)Space travel involves extreme temperaturesSiC has the ability to operate in and withstand extreme temperatures (>500 °C)Problem detection = Problem prevention! Spacecraft problems have proven fatalKey Specifications Increased Sensing Range 25 ° C to 500 ° C Operating Voltage 5 volts to 24 volts Tolerance Temperature reading is accurate to 0.5 °C at 25 °CSystem Components•Temp. Sensing•Voltage Output•A/D Conversion•Serial Interface•Temp. Display•Advanced FunctionsPrototype Layoutp+ n-Metal Contactsn+ n+Doping Levels 5x1018 1x1016 Design EquationsR = *(L/A) A = W*t = 1/(n*q*n)Ni = sqrt(nc*nd)*e(-Eg/2*k*T)n = (2.5*107)*T-2Si & SiC Plot of Resistance vs. TemperatureR vs. Temp.0204060801001201401600 50 100 150 200 250Temperature (oC)Resistance (k ohms)Test Spec of 25 to 500 degrees CSilicon CarbideSilicon0 50 100 150 200 250 300 350 400 450 5000123456x 104Temperature [C]Resistance [Ohms]Controller Board DevelopmentToleranceThe tolerance goal of 0.5 ° C of accuracy was metAmbient Temp Calculated Temp Absolute Difference Calculated Temp Absolute Difference Calculated Temp Absolute Difference27 26.906 0.094 26.906 0.094 26.906 0.09427.5 27.499 0.001 27.499 0.001 27.499 0.00128 27.972 0.028 27.972 0.028 27.972 0.02828.5 28.446 0.054 28.446 0.054 28.446 0.05429 28.919 0.081 28.919 0.081 28.919 0.08129.5 29.509 0.009 29.509 0.009 29.509 0.00930 29.981 0.019 29.981 0.019 29.981 0.019. . . . . . .. . . . . . .. . . . . . .497.5 497.635 0.135 497.635 0.135 497.635 0.135498 498.052 0.052 498.052 0.052 498.052 0.052498.5 498.608 0.108 498.608 0.108 498.608 0.108499 499.025 0.025 499.025 0.025 499.025 0.025499.5 499.582 0.082 499.582 0.082 499.582 0.082500 500.000 0.000 500.000 0.000 500.000 0.0005.2 Volts5.0 Volts4.8 VoltsOperating VoltageVoltage Regulator output varies from 4.8 to 5.2 voltsThe desired accuracy is still obtained with this variation50 100 150 200 250 300 350 400 450 5002.42.62.833.23.43.63.844.24.4Temperature [C]Voltage to input to A/D [V]4.8V5.0V5.2VCost AnalysisApproximately $2000 per substrate (2 inch diameter wafer)Approximately $600 for whole-wafer EPI GrowthApproximately $400 for Fabrication RunProducing 25 devices per wafer, and assuming overall yield of process of 72%, produces 18 usable devices at approximately $167 eachControl board components: $26.61Total cost for working unit: $193.61Determined the limits of Pspice with respect to SiC modelingUtilization of MATLAB for simulations of SiC device and controller board circuitryDesign will be later incorporated into a single MEMS device for determining temperature, pressure, and vibration from a single point on a space vehicleConclusions/Future WorkSilicon CarbideTemperature Sensorfor Harsh
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