Abstract
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Frequently,whengrowingIII–Vsemiconductorsongermaniumsubstrates,unexpecteddifferences between nominallyidenticalsubstratesareencountered.Usingatomicforcemicroscopy(AFM),wehave analysed asetofgermaniumsubstratessharingthesamespecifications.Thesubstratescomefromthe same vendorbutdifferentresultscomeaboutintermsofthemorphologyoftheepilayersproducedby the sameepitaxialroutine(i.e. substrateW1 producedepilayerswithgoodmorphologywhile substrate WX produced epilayerswithdefects).Themorphologicalanalysishasbeencarriedouton(a)epiready substrates; (b)samplesafterahigh-temperaturebakeat700 1C; and(c)onthesamplesafterahydride (PH3) annealingat640 1C. Inthetwofirststagesallsubstrates(both W1 and WX) showthesamegood morphologywithRMSroughnessbelow3A˚ in allcases.Itisinthethirdstage(annealinginPH3) that the morphologydegradesandthedifferencesbetweenthesamplesbecomeapparent.Afterphosphine exposureat640 1C, theRMSroughnessofbothsubstratesapproximatelydoubles,andtheirsurface appearsasfullofpeaksandvalleysonthenanometrescale.Despitethegeneralappearanceofthe samplesbeingsimilar,acarefulanalysisoftheirsurfacerevealsthatthesubstratesthatproducebad morphologies(WX) showhigherpeaks,andsomeoftheirroughnessparameters,namely,surface kurtosis andthesurfaceskewness,areconsiderablydegraded. | |
International
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Si |
JCR
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Si |
Title
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JOURNAL OF CRYSTAL GROWTH |
ISBN
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0022-0248 |
Impact factor JCR
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1,95 |
Impact info
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Volume
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310 |
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Journal number
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23 |
From page
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4803 |
To page
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4807 |
Month
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ENERO |
Ranking
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