Key Technologies Of Design And Processing Of A Novel Temperature Sensor

In recent years,graphene has been widely used in sensor fields due to its excellent thermal,mechanical and electrical properties.The temperature sensor made with graphene as the sensitive unit has the advantages of high sensitivity,large temperature measurement range,short response time,etc.so it has great development potential in the measurement of temperature environment.Based on this,this paper proposes a temperature sensor with a boron nitride/graphene temperature-sensitive junction as the sensitive diaphragm and sapphire substrate as the thermally conductive diaphragm,and its key manufacturing process and temperature-sensitive characteristics are studied.This article mainly completes the sensor chip structure and process plan design,sensor process manufacturing,temperature-sensitive characteristic testing,characterization and analysis.The main research contents and results are as follows:(1)The overall scheme of graphene temperature sensor is proposed.Based on the heat conduction mechanism and thermal resistance effect of graphene,the temperature-sensitive mechanism of single-layer graphene is briefly introduced.Graphene is used as the temperature-sensitive diaphragm to realize the conversion of thermal signals to electrical signals;sapphire is selected as the heat-conducting diaphragm and passed through the finite element method.The simulation design of a reasonable heat transfer membrane meets the requirements of sensor design indicators;the chip process plan is designed based on the sensor structure,and the design of key processes including heat transfer membrane preparation,electrode wiring design,and sensitive junction patterning has been completed.Corresponding process flow sheet was presented,and the mask design was carried out.(2)Finished the process of making graphene temperature sensor.Completed the production of electrodes and wiring,the transfer and patterning of graphene nano-films,and the production of sensitive units;detailed introduction of the growth principle of atomic layer deposition Al₂O₃ films;completed Al₂O₃ protective film etching process,detailed introduction of ICP etching Al₂O₃films The basic principle of the Au Pad and platin?m wire bonding process test,determined the appropriate bonding equipment,bonding materials,and proposed to meet the temperature sensor chip wire bonding process requirements.(3)The test and analysis of the graphene temperature sensor have been completed.It is determined that the best thickness of the Cr/Au metal layer to withstand the 900?high temperature test is 100/800nm;the best bonding process conditions of the Au-Au wire bonding orthogonal test are bonding force 69N,bonding power 190W,and bonding time 150ms,The search height is 0.2mm,and the diameter of the bonded platin?m wire is 50?m or 100?m at a high temperature of 900?;through the study of the temperature-sensitive characteristics of the sensor sample,the sample resistance is about 6.551Kohm,the IV characteristic is linear,and the stability is good.The resistance temperature characteristics of graphene at low temperature(45??155?)and high temperature(25??585?)are introduced in detail.The B zone(-25??60?)and F zone(260??585?)The sensitivity is 0.13%/?,0.16%/?,and the linearity is 0.9972 and 0.9901 respectively.The calculated repeatability of zone B is 5.14%,and the hysteresis is only 3.77%.The h?midity interference is studied,the result It shows that h?midity has little effect on the test process;the Al₂O₃ films,sensitive junction,substrate and ohmic contact area of sample were characterized by scanning electron microscope,atomic force microscope and Raman spectrometer,and the reasons for the failure of the sample were analyzed.