Institute for Materials Research University of IMOMEC Associated Lab IMEC monitored in-situduringlife test. under test (DUT). parameters oftheDUTsThe electrical are 250°C. Stress voltages upto 200 V canbeappliedto thedevices The system furnace iscapableto operate attemperatures upto sation ofthedevice undertest duringlife test ispossible. be seenonthegraph (right).Bythisway, acomplete characteri- through different stress conditions, user-defined anexamplecan software. This allows acquisition software alsothecycling The measurement process iscontrolled by dedicated acquisition degree offlexibility. temperature profile are definedby ascanlist that provides ahigh monitored duringlife test. stressThe conditions electrical andthe components. ofactive ity The ambienttemperature isclosely heating isamaincontributor to theageingandthusreliabil- internal level. self-heatingataconstant, well-defined The self- current (power) mode. This modeisusefulto keepthedevice The devices canbetested inconstant voltage andconstant Characteristics life test. relevant electricalparametersaremonitoredin-situduringthe 20 devicessimultaneously,40powersuppliesarepresent.All device undertestareneeded.Asthesystemiscapableoftesting gate terminal.Thereforetwoseparatepowersuppliesforeach collector ordrainterminaliscontrolledbyasignalatthebase Transistors are“three-terminal“devices.Thecurrentthroughthe known inadvanceordertogetreliabletestresults. occurs. Thisself-heatinghasalsotobemeasuredoratleast generally higherthanforpassives,significantdeviceself-heating signals. Asthecurrentdensityinsidesuch“active”devicesis are called“active”becauseoftheirabilitytoamplifyelectronic and inductorsbutalsoactivedevicesastransistors.Transistors comprises notonlypassivecomponentsasresistors,capacitors The applicationofelectronicsintheautomotivesector Testing self-heating Application area: components electronic active Test System Active Components Electronic I c current I c • High degree High offlexibility • duringlife test ofambienttemperature Monitoring • Stress voltages upto 200 V • System furnace upto 250°C • Dedicated acquisition software • Simultaneoustesting of20devices • duringlife test Complete ofthedevice characterization • electrical parameters monitoring ofallrelevant In-situ • (power) mode Constant voltage andconstant current • srs I -stress I c @U Electrical stress setup cycle Electrical cycle 1 cycle 2 cycle 1 cycle BE-step c -stress Time System description and specifications

The test setup is able to stress & characterize up to 20 active components simultaneously in 3-terminal mode (e.g. transistors) or 40 2-terminal components (e.g. diodes).

Parameter Specification Temperature range 30°C … 230°C Temperature stability 0.05°C Supply voltage -12V … 12 V Maximum supply current (base) 30mA (fused) Maximum supply current (collector) 300mA (fused) Maximum current measure range 1000mA Maximum measured voltage 200V Measurement resolution < 0.1% Measurement capacity 20 (3-terminal) or 40 (2-terminal) samples simultaneously

Measurement example

The example (right image) shows degradation of the amplification factor of heterojunction bipolar transistors (HBTs) stressed at 125mA collector current and 120°C ambient temperature. At this ambient temperature, the device internal temperature (junction temperature) is 205°C due to self-heating.

Temperature dependence of the HBT thermal resistance Degradation of the HBT current amplification factor

The self-heating depends on the dissipated power, the ambient temperature and the thermal resistance of the device (left image). The device self-heating has also been determined with the active electronic components measurement system.

IMEC Institute for Materials Research - Kapeldreef 75 Division IMOMEC, IMEC vzw B-3001 Leuven Wetenschapspark 1 B-3590 Belgium

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