The Development Of Automation System For Lock-in Carrierography

Microelectronics,optoelectronics,sensors,photovoltaic energy and other semiconductor materials and devices are closely linked with our lives,both in the common industrial areas or high-teach world are playing an irreplaceable role.The development of the methods of detection of the crucial physical parameters and carrier transport properties(front-and back-surface recombination velocities,diffusivity,lifetime,mobility,etc.)that reflect the performance of semiconductor materials and devices has naturally become a main event in scientific research field.In this paper,the Photocarrier Radiometry(PCR)and Lock-in carrierography(LIC)are the most promising detection methods in the field of semiconductor materials and device detection.Photocarrier Radiometry,a form of frequency-domain photoluminescence,spectrally gated to blocked out thermal infrared photon emission form photoexcited semiconductors,and Lock-in carrierography,the camera-based imaging extension of the single-element detector PCR.Compared to Photoconductance Decay(PCD),Lock-in Thermography(LIT),Photoluminescence(PL),and so on,which are already present in the world,the Photocarrier Radiometry and Lock-in carrierography have the advantage of high signal-to-noise ratio,capable of all optical,non-contact,and non-destructive measurement of carrier transport properties.What's more,they are already applied to varieties of semiconductor devices and materials for carrier transport properties measurement.PCR and LIC technology in foreign development is very mature,but still on the initial stage in China.Most of the work in the experiment is complex and time-consuming and need to keep manual operation.To achieve the system automation design is the problem demanding prompt solution.In this paper,based on the theory of PCR and LIC,the main contributions include four parts as follows.First,combined with PCR and LIC detection theory to complete the optical system construction and the whole system of the feasibility test.Second,the whole system framework and workflow was determined and finished the every module programming with Labview and C++ for each instrument used in the experiment.Third,combined the LIC and PCR system together in proper way,and analyzed the various factors in the system,then corrected the error.Fourth,the silicon samples were detected by PCR system and LIC system respectively.The experimental data were compared and analyzed,and the transport parameters were calculated.