Daim ntawv thov ntawm microscope hauv kev lag luam tawm tswv yim LED
1, Taw qhia ntawm sapphire substrate cov ntaub ntawv
Vim lub zoo insulating zog ntawm sapphire, dielectric poob yog me me, kub tsis kam, corrosion kuj. Zoo thermal conductivity, nyob rau hauv lub mechanical zog yog siab txaus. Thiab tuaj yeem ua tiav rau hauv qhov chaw tiaj tus. Transmission band yog dav. Yog li ntawd, dav siv hauv kev lag luam, kev tiv thaiv hauv tebchaws, kev tshawb fawb tshawb fawb hauv ntau qhov chaw. Nyob rau tib lub sij hawm kuj yog ib tug zoo substrate khoom rau ntau yam ntawm lub teeb-emitting diodes. Nyob rau hauv lub cim ntawm lub teeb-emitting diodes yog * cog lus los ua ib tug high-brightness lub teeb-emitting diode tsev neeg ntawm sapphire substrate substrate los ntawm cov tiam tom ntej ntawm fluorescent teeb, semiconductor light-emitting device substrate cov ntaub ntawv. Tam sim no, cov high brightness lub teeb-emitting diodes tau dav siv nyob rau hauv advertising, tsheb teeb, ntsuas teeb; thiab phais teeb thiab lwm yam teb. Nrog rau daim ntawv thov nce siab brightness lub teeb-emitting diodes.
LED Sapphire (Sapphire) yog ib qho siv lead ua ntawm txhuas oxide, tseem hu ua corundum. Sapphire siv lead ua muaj cov khoom siv kho qhov muag zoo heev, cov khoom siv kho qhov muag thiab tshuaj lom neeg ruaj khov, lub zog siab, hardness, ntxuav tawm tsis kam, tuaj yeem nyob ze rau 2000 degree kub kub hauv qhov hnyav. Raws li kev tshawb fawb, tsuas muaj plaub cov ntaub ntawv substrate tuaj yeem siv rau LEDs (saib Table I hauv qab). Sapphire, raws li ib qho tseem ceeb technology siv lead ua, tam sim no tsim ib tug ntau fashionable thiab paub tab daim ntaub ntawv nyob rau hauv LED kev lag luam.
2. Cov ntawv thov
Siv Leica's polarizing microscope nws tuaj yeem txheeb xyuas qhov txawv txav ntawm cov pob zeb sapphire. Nyob rau hauv qee qhov xwm txheej, nrog kev pab ntawm lub khob iav lub teeb, koj tuaj yeem soj ntsuam qhov cuam tshuam ntawm cov qauv siv lead ua, txiav txim siab lub axiality ntawm cov siv lead ua, siv los soj ntsuam seb cov kev taw qhia ntawm txhua lub wafer yog qhov sib xws, txhawm rau txiav txim rau lub substrate zoo lossis phem.
Leica microscope, scanning electron microscope hauv kev tsim cov LED epitaxial wafer, LED nti npaj txheej txheem kev siv
1, Taw qhia ntawm LED epitaxial wafer
LED epitaxial wafer kev loj hlob ntawm lub hauv paus ntsiab lus yog: nyob rau hauv ib tug piece ntawm cua sov rau qhov tsim nyog kub ntawm lub substrate substrate (tsuas yog sapphire thiab, SiC, Si), cov gaseous tshuaj InGaAlP tswj thauj mus rau saum npoo ntawm lub substrate, kev loj hlob ntawm ib tug. ib leeg-crystal zaj duab xis tshwj xeeb. Tam sim no LED epitaxial wafer kev loj hlob thev naus laus zis tsuas yog siv cov organic hlau tshuaj vapor deposition txoj kev (MOCVD)
2, LED nti qhia
LED nti, tseem hu ua LED teeb-emitting nti, yog lub hauv paus tseem ceeb ntawm lub teeb coj, uas tseem hu ua PN kev sib tshuam. Nws lub luag haujlwm tseem ceeb yog: hloov hluav taws xob rau hauv lub teeb lub zog, cov khoom tseem ceeb ntawm cov nti yog monocrystalline silicon. Semiconductor nti muaj ob feem, ib feem yog P-hom semiconductor, nyob rau hauv uas lub qhov yog dominate, lwm kawg yog N-hom semiconductor, nyob rau sab no feem ntau yog hluav taws xob. Tab sis thaum ob lub semiconductors txuas nrog, PN kev sib tshuam yog tsim los ntawm lawv. Thaum cov tam sim no ua rau lub wafer no los ntawm cov hlau, cov electrons raug thawb mus rau thaj tsam P, qhov twg cov electrons yog compounded nrog lub qhov, thiab ces lub zog yog emissions nyob rau hauv daim ntawv ntawm photons, uas yog lub hauv paus ntsiab lus ntawm LED luminescence. Thiab lub wavelength ntawm lub teeb, uas yog xim ntawm lub teeb, yog txiav txim los ntawm kev tsim ntawm PN hlws ris cov ntaub ntawv.
3, Kev siv:
a) Siv SEM txhawm rau txheeb xyuas qhov dislocation corrosion morphology cov ntaub ntawv ntawm cov khoom siv lead ua tom qab epitaxial wafer loj hlob;
Qhov tseem ceeb yog muab los ntawm dislocation corrosion morphology ntawm cov siv lead ua nto: qhov dislocation corrosion ntawm txhua tus qauv nthuav tawm cov duab sib txawv thiab cov siv lead ua yog nyob rau hauv pawg ntsiab lus thiab cov qauv ntawm cov siv lead ua yog txiav txim siab los ntawm lub luag haujlwm ntawm cov tshuaj corrosive tus neeg sawv cev yog los rhuav tshem cov molecules. thiab atoms nyob rau hauv cov siv lead ua kev sib cuam tshuam ntawm kev sib txuas, kev sib txuas ntawm lub zog me me ua ntej yuav raug rhuav tshem, thiaj li tsim tau ib qho zoo ntawm corrosion ntawm corrosion ntawm ib qho chaw, yog li ib tug zoo duab ntawm corrosion ntawm corrosion ntawm lub qhov chaw tau cov ntsiab lus ntawm ** rendering, tuaj yeem ua tiav hauv qhov zoo ntawm cov qauv siv lead ua.
