DTIC ADA431005: Investigation of Structural and Electrical Defects in GaN/AlGaN Structures and MODFETs

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SERRA RET TOOT
iv hs projct, min goa wast Focus on MMODFEET siruues to uadersind (be sect ut saprovenens aot be oases 0
agra, In order to raceme cf ta besve. Ue CaN copies yrume by MOCVD st flse Ny c-sa
vagocuion oT aye. By the ees of iia nason ia hydrogen nd snuzenin caviar leds he MOCD sya
in Ti ayer ae conver its az etelive naan netwuek ul SN shih deity 0 sods att sana poses CaN sade
rises nanan Ca lenges were ese 3¢ 2 ema or nane-TRD epitny fr CAN grant

ss early ben reported Ue plow of ck CaM oa sequel separating for apni sober by avo eee
sepicaion (VAS! ecru, wich ulBzek a hr. THN sans nwa 2t dc kegining ot hydride vapor pase ein
uterr grown ey obtained a ers low TD desity of Set em— fer ho 30 em CaN lye om th THN el e,
ese epee by HVPR gro calcein such CaN iemplares withaoc a TIN eco. Wis, heetore, sce o deter}
se re of THN aswetk nelson roduc in inner CaN Hest sper, weep Ue Ee ee
coaetcterinstion of CaN grown a i i TY pore nstserk by MOCVD with setced ditiallon ancy and het
npc teal an xyaline ropes.

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Anvestigalon of Steturs! ana Retreat Defects in
GaNAIGAN Structnes and MODFETs
vie

MODTETs fibre ow CaN filus show a cumbor oF deviations Sow ths
‘ol sinvttes, The snc wil henson ths rset ety cours of imprest
ppuhe Yo ubdertnd to sources of degradation. Ibe porary focus all be un
IMODFETs, bur the rvs will be appiable a bast range uf wine devices.
Lesage esocted sith tie gates <f MIDs # a geimaty Tinstzion in devie:
peclnmanse, Corel sdkige gals, ae who purs'asne phntacontuctsiy, 30
Cent ag aul cure ealape, ae cated to clseuiealy active docu, suriace
inorfee stats, and mel indneed sup stres QHIGS). We vil impiore devi
sapabltisthrovgh severat mesa ceablions (og, tengstae, WML to),
(rowh melied fe, panrT RO, TVPR. telus, ecing and regrow), and pos
morh pusivation

Progra

Diet reduction by tanto ntrde uanonee

this pujet aa a! vest fous on MODFET sousrrcsr aadertand
the sunoesatngraernes aad th sees of degedao, I erdert ash oar of
the ehieaves, the GaN trplace erova by MOEND wes falloved by e-beam
‘eaporation of Teper, Hythe aaa of oi trio in bye el roa
cavionment inside the MOCYD yeti, this Ti Iyer was coven tv av efetive
ann netic of TIN sh high densky of voids and aexo-porns GaN ier, Thove
anauo-potein GaN teplnes were weed osu Sept Li nemo £14 epibny for
oath

eas seaentty heen reported the aroerh of tick GAN ara subsequea:
scpwaion fort sapphis aubere by 2 veidassiee! sear. (VAS) tehmigue,
‘which ulizge a cb 15N porous etwork at ibe Drang of Eel wager phase
eplany (IVPL) srw! They ube way low TD density af S10 an? ete
$e-jr Ga ayer on the Terk, was eeparted iy HVPE goon elie ia
Fah GaN tsoptces witht TN network” Ici hecfore,icteverting to derzine
the role of THN aesoth uo slum etn thinner Ca Te 8 oe,
sve report te growth ard saratrition af CANT grey on ua he TIN poses
fete by CHV ih eae cilncaron an and heetee improved pec?
and ogein ropes

Tor tbe HIN Liver expect, 4 UT yn GAY grows se sain by MOCND
sa se i emplatien J ies of ZH an a Ma Wore obeam evaporated on dio
GaN tenpltes aed then abject ena terval aneating proces at (000 °C for
shuts, for 9 Rod rave of Myo , (3) cuts inside che MOCYD chamber, Gud
verso as Dea mede on these Foo temples f 1939 °C, orth consist TMG
Tow tale of Ts yeni an Ml Mow tle af ¥6 Lin, Fa cempcsoe ¢coata)

20050325 134
GaN layer sue grown em the se Gat) telat ish. enti gro contin
bout witout the 13N newer, The Gi vimgle with 20 ain TN Tager ras
Cacia’ sing erie an] parece nenaisting elton mies
(TEND, logebor wih he coe sarple. Table I sunmarizd the gro condita
‘nd elastin, eu ora te erage

(omen

“Fab 1 a ad tyes gn 2E tad Un TR porous etn, la the
‘ol GaN ler woo TN, Tae HRD ce cad tn>-esobed PL dat ne ewan
tere

Fh samples wore haracrid hy seaming eleion nisseeo3e (SLM).
vay difisron QXRD), and room tempersure Unsesesolved poloiuminescets
{TRPC), SEN images show tha the sac xunpboloyy uf TN euvere serge Is
souls acted by annealing ame, bul Wa tener ele Oy cifras aia and
seualiog ieuperturen Tole song prove, micseane windows weve Soros
‘on te lear dun desorption of fo Ti layer at high empertpe,aecorpsnied by
niuideion of his scorigsous Tec fe TIN meswork Alte ine ean
sgn lee chins sere nd a1 wha feats ae of 2m. & sist
hencwsenon wae als repotad? We suggsst hat hese small windows (chan) Sst
appeared at giain boundaries of urderving GaN wnmplate at the inieal age of
ividagon, Th es porous ante of GAN ute sain bonds aml 9 ube
este elect of Tun GaN decoxositin ed us Los mest «By he fata
Snneiling preci progress, nove wont agin to format Be sala bandas and
‘unegovall bch De deny aul ses of ise vidos inoease sd time. Fgus
(a) shows he SEM sartacs momphalogy oF TIN poreusasrworkformod onthe 20 ren
‘Te lyse. The cos-cticnal TEM scrogrpb tor the GaN wth the 20 om TIN
porous aeerk is shovm in Fy 1b), Neer be ser tt Nee GaN grt he TIN
Dore netrk iad Irn he o'amenne windows nf ths dioecious TIN
‘stink abting a2 GN itends. THis flowed by the gion of Ga eer
‘from ths istnds by lesa and vical expansion leding 0 enleseave, Ibo be
creel thet bin er ll subareas De dct TNL
Tagen de oe aeralavergrvil of GaN a tho poste “aninactar: cee” of
Tint Thvcatingdsioatonssignifcatiy decease ato above the TINGS intertce.
Avast hoo mestimisms can be Euggese for esloclion reduetun elt 1 Ost
poor on LIN porous alec. Fs, ont uf the Ucaingdisooains hho GaN
fanplate are effectively Meckod by te TN layer, Scrand, some ending
Alslosatogs pstemee zpugh te TIN wéndows tothe epper lier but sreadpans
hange their propaption Unertan and extend lateral inezad. Th the near
Aiiestion-fio region above TIN, wore plane slacking, aie aro Joissd dus to
ising ond dsovilion of dalncrinns inte pera. Burgers vorear pecmig,
Soul dsketi tedeioncna'd oooae rough recomblonton and samba,
There, the pipapaton of dslostans i eflcsvelysupprete:|avar Ue INGA
Jive, For compacieon dhe somal GaN ler grown wu! the PN incr is
shown fs Fig eh wich shave no observa. Ustcslion sation above che iit
GaN teupiae

ice 1) SUM aN png wa (29 49 Tar, od Uy ean meg in
Niet (ith. Gone lina 12M ast th efor 9 11 poroe star Con 2D
Taran Gia ietionreducizg (Gas ge sur oe

A precise artoviment afd amar of dislocation celoutvn cat be mae by
cenuncig neti de delcrion inthe plz. ew TFM ocengrapbs. We Fig. 2il,
the Pai-view image of ube Call opabel Ieee gteson srtheut TiN (03 jam
thickows} sath density of og cislaeaeon aerays (1.5 «108% se meee
by "e, aud 2 much lower deity of iit endnn sors dioeaions (13
hem) os mario by "Far te GAN gjoxt vith 20 nu TN porous retner
‘hin of onty 15 gin shown in Fig 28), he sere lc daly 5 alee
rchanged (1.4 = Ue bu the ihe slacations (0.9 > 10'n') ve
Seeresed bya estan onder if engi, These avis nagar saggea het te
{Win FIN parva ucivrk wedi very sffsotive in reducing edgo dislocations. Lex
teow Glocatin, hei maniher ero aleney lowe {abort 20% uf Ue tal
‘Selowzrng) in MOCVD GaN, and the effet of Luh iz rediing Drm i Hares
Issa kely. Hlghresclliea sty rocking coe (sa) shor hac the GaN saaples
‘row on but 20 yn nt 10 ny TIN porous runes have Srproved eying
(geahy fa ters af he fa-widtha-halznesimure (WLM) 0° Ue asyeuclic
uO?) aitzaction weak, az cane sen Tle Speielly forthe GaN eaaplss
‘eith 2 am and 10 0 TiN pucsus elves, FFM of (1012) jouks are 5.4 ari,
el 45 gr, easpecczaly, ax comparee to 7 aon: the congo) empl e
ie onsistnt with die TEM nels i Lp. 2, which xo 10 « ection ‘hs ods
alocacoos conmunly wsovined wis He asyarnctie (1012) beeadoning whisa 5
tecuilive Wb edge daoestiong. The wally unetlected srumevie (002) FWLIM ic
‘Sonsstne with tz TEM micrograph shoonay unebungel are locaton desi
‘TREL is uondestietive and ponerfl fecha evenly sed te measure earie
serine am impure parca ‘clad reste quality ax device pekemmance
Figars2o shoo theron tempenmure THPL data fr the CaS corto sz <8
in Dhoirs) wich xo LN, az the Cats sales sh 16 cm ane 20-3 TAN porous
avlyuchs, Th tivecesoved signls vere idegated over x 10 ama wie spsest
Teun Site peck PL encigy (24 eV), The inetemeea- hile ge ples tae
the estvation progenss ena the canes fom 4 eV enltalion anespy-dstacd
Hates to the 2000 qoinearim eavilooe bir ge sites are very fs For ash
favcpls, th doveying part ofthe TIL dt is wo! fest y a bexpancotal
Alecay fmoloa: Ay expla | A; egy) Table Tiles Cr decay cure 3,
find) nd Se amplitude ratios AFA) ub fate 8

iy @

Fieve 2, Plows THM riangngle smi oye ate srw dante ithe on of
aN rae, 1) eh eel spe ween TN, a he CS ih 2 mT
res, (e Ginteasesd Poe. sobrg Beexgmenisl day eae ties So
{GaN groan TN pose deracts ani 29 yon ond rey lene, an willow TI
(eon,

ay constant sal prbebly repress effeiveno-aitve
seeumbinatioa st room fexpertoe, se she decyleg,enmponent tis arise co
the raskaivs Tiling wf The hoe exciton, Compared ee cancel snmp Co
sens wit 10-am TAY porces work she alm! Biter o 2 imgeceancn 0
the curler fete fr) be dy eres for Ure GaN sang th 70 ow TN een,
{esl to ther fe te conte ensle, However, di elative maga of fe ese
<ssaging comprnont to the fat desepingeomponen [AIA fr bh af he sales
‘eit TOR netwodks ae igroved compared i The vorenl eres This ioaze tat
the noaradve reeembiation is mute? by Me inclvcn of the TIN eras
network, Te vansierah isc: in he ctr Bifedne (rn) Yor the 19 ou TEN
hee haw the 20m camp i sane puzaing mace the RD daa Ker
sane me sir arcs, oweven ane nd kao ind
‘hatin adaion to the feaing alors, the warty Time ie 3t0 ssn to
ther ype of defets euch a pil dose the fet oF whic ae not acodeted by
[XE ates ls with ately broad ay cifSncion pes.

Distocntion reduction by woectiv etch
‘The arlectvely etching of the dslcitvy diets ard peition of an

‘The aeketiveeshing af dip detective rons wae cae og, by erin wih KOM.
Some pet ofthe samples prowe 2y ZC VD technique wo beste wil noon KOH.
{1210 °C, ont for 2 sosome an ons fee 39 seconds, Thaa overgrowth of 2m of
‘EAN on the KOM elehed and aon-etsd som GaN senplt sone it 1020 °C,
iol. a Mg-Coped layer 200 sen ere oe prow lo frin ap fneton. Blstioal
mewimeren, csi yeu vllage -V), ws aloo perforined ard this measinemen!
showeé sir leakage cutee: fey all of te beatuents. Lhe eect va the chal
"rfp sven Fig 3. KOH ctchig for 2 ee eches sol pits athe solace KOH
{ething fr 30 sos opens up the gt argerbesaponsl sie

Sustral aad opis eavictaratinn i nt vevcal any sgnicant dtersanes im he
alr! properties. Ria Pacing 6x width ar bat manna (WHIM) 47
AUR arom tor te (002) ine, with aegligile ville betwee he etched and
grown, and neeathed erd regomm layer, The (102) line wie 69, 25, aud 6S,
seria fo he noo-cched sample, the sma ecm! for 7 st, an he samc ee
fe St) aos, cemportvely. Bhocolmminesoenze specks shotee vary salar
haretriones for ail sample, wih r9 Satnguiehing diernces af can he
Figue 4. UhebW1M of ke ecilon peaks a ISK rage fom 4.697 a.

aces

aime Beer

ge 3, APM ings ofthe templates for regrowth of aN by MOCVD, Behing fr 2
conde ich nen pp Longer ROR ska etl

Pe amt

haem e918
zw pea lta forgo st GaN by MOCVD.

oop level mansient peckoscupy (PLES) sae ual tu meus ths daft
conceastion far each ofthe healaes, ok well a6 the dofor uorgcs a exptre
‘uns seston, The DETR sor i hare oa a SULA system, vet added digtication
‘of the trnseot forrati-espenentileomponeal (ih, revert seenate at cach
fenageretre stp were ootized by averiog 20M) rawioits wage, aking “50
pins ot O1 meve sampling inlercls Me ilkng oulee with was 10 rsce. The
fensgerstre ws vaio i 4 aps fom $0 19 700 K

“Tue sate ovindow plot fort cont sample, andthe samples vee ix KOT
or 2 and 30 sozoads ia Fgue Si} shoes several aps, rot his rater doo ph,
fppnote tha the 2 scood etch in KIT was ens ofztve at reducing ths wos
promt bap a1 340K. ecmparznn af fo eae wind plots for sevecal ses
Eom diodes proceed Metcally real tat >a variction in the evocation of
‘uape wee uoaly ab lrge as those sex cm Wg Hower, es bap eomecteation
at 340 K was soneitently lor (oe de war etched fr eccoads compared ta the
fone) sims, or Ue srple ekdal far AN seonde. Behite tor 30 seconds
produced same of Ue highest conceration rps at low temperature below 200 K.
[Rone of fe etching iralvens lisiated any speci 2aps. The Acaheris pts
iver in Fg. 0h) shoring the oberg for ho electon and bole “ops, able J
suds the characterise of eash ap. The bole tap at 75 me bys rel been
reported previcealy, mor has the obieraton af werlipping rape ak 300 380 K ih
cuore 620.536 eV and USNS eV.

Figure 5. (4) DLTS sosindce epee fr MOCYD roan GaN Ta fmwvong carparng
‘he mnatod roi conse spe, 0 CoS eich or De Sacer KOM pe
epeuth, The eccaeren simon woe 9¥ alg ple. 1 renconcn B (e
ero ty ater ont The aeinde i 20. QD) DLTS Asians Pot aps 624
{SF nd GSE we eonttnly act o-Gat grove by erm tne The eee
[ims amd he tap sh 1506 eV psig ih he ana taps 385 0 ave ot
een merely
“Tw caprte irae wore al studied os w meas (u dicate hetoen
peiat defects and Ungar defers, auch a2 dislocations, Copsctance tatcont
Eplindes from dslaeatins buve tee shaw lo ive gels dependence 00
‘ing pole width* neressng Ihe firg pols fam L pase to 269 mace fee the
at 346 K rested i «lavas vee inspite ne: plotted veras the ly of de
Sling pose wth snating thet te kap esate o aloaoos The tp at 12
Swed a chaage i easier: ample when varying De ii, yalss wie mt L
ros co 200 mice st the respunie ns cowplirted Wy the meatal maar of ie
‘8, which ie dscosed wet

“The conceanation of raps mesure a eupecarnesbslaw rece omperanre
pended onthe conditions shning cocling, The 40p level spore in ig. 6 were
‘llected tnder various comlions svi caning t 80, neudirg 9, 130 aA (or
ier A. 190 minutiae ia pap and cepsoo) faward eure, iad "30 Ys Thee
Siow thar th confguaren of dafex structure depeuls one evans uf 60005
Jing eloseally active when fx Wap se ill Fillet, ia otha by Wo,
cal [5. There aio a aautig ffl a9 sexe poviouly “show bythe Bee
‘ate sper iene not ng its 10 V applied i high fh “he 2th hen
wll ¥ sooling, AS a rvul of tis cbsecation, all of the spelen Fig, 2 were
‘Renvded after bestng to 700 K, and wah 150 ro applied doving cooling to the
Sartngsencpeatre of 39,

Further mpimremenis of the TTS spectra showed that the arence
‘ete concent af aps was at pesathennsen dese oathe seme piece, ws fe
Aiioence beeen arene tretmans, "This bus 9 buen weeu by ollers (Foss,
[WSU fe odor MOCVD samples,

Vigane 6, The conan 9 dep ‘atelea€ 161 K pied or the enone arr
‘fing indcalng strane cootgtion Ale, the ar meng eet woe be
pee a aes 10 a beer thm the era er OW. Tho wer Bah Be
spoon wore oer Tp ¥, 24150 pA BOY.

MRR grate Aneto for iat ety

RGA. RHEED, oul AFM netiatshavs bacn used to delenuioe the desorpiva
‘al Aisin ossaios of vavious zpcis ueoted in te ere ith BF mogen oe
SSnvconia and molecules of 8-C, Theoneray ie detrmed a a uceion aera
‘Srection hy espost he ze using cthing ane geont

‘allies (Ga) eurece deseyion >eivior was ineesgalel ass efleion
ighorergy elton eatin {RHFBD thing the GaN g-cenb by plato ast
amalechr bes epltay JPA THF 1s Hon ha the Anton nf Ga tors fom
the (QUUI) GaN curves yrlerdifrent TV ratio Acviatsr ftom the zorot-rder
nee neha the devon ei independent ofthe coverage of adsorbed slam,
atough witha egal empertursrerge unde the same LN’ rls, the weoonlor
ines can be applied to fou oul Ue desorption energy appusiaely The
azeoptioa eagles tae dlermine be 2:18 eY on Gea foe Ga deoplt, 29 c¥
Toe Ga under Goch growl wntion. and 042 eV ~ 224 o¥ tor Ga under
sloichvnrtceqrouth eoians by maoite: the const change of REED sper lar
besa diag de gro, The ona lion ofthe GaN sorace marpbology varnog
nee difetent THY ratio ow porses completes zatehes the result ub the Ge
Assptoa energy dependents othe coverage, and IIA zl Comune the wrath
riod

Molecular beum epitiy CAB: iy» provisinn thd fr fabrization of Gat
bignt forteurtns deviogs hors hgh por and precise coo! of yer duchess
22S royuited anes thas ploeee contol of he berm Hanes end owt conditions?
Maroover sit characte wus St BL asstew saa 0 yrs
‘enc bed gon eth dares. 80 fr Tigonting isd, aor ends
UV pholgdsasn and eterjuneian field efit uansiters” have been produced
Ang GaN hoveticd fox tc expablties ef MBE. Tse comprehensive sly of
thesia ap deviee opens Rave beracamed out conceming some sila,
paver for gronth be pla wised mufeclar bean eplany’ (PAMTBY
However, the itensve work un epitaxy of GaN for ec apiations sf contrasts
atte fe states nn ihe glgsioe af goth isel= Only rocoely, gow: studion
‘sl MOVE wc Ul the ipo ncehahian and the revoking eurace seustne cE
(ak tin las are emily eenstve to the ine, i. G3 lo mt aa pot
feuperacae tin roported tt che to-cersiont gol, which i ese for
‘este Lito, ie eoerrumly tial unto Cheri eondits 6 e Cacrich
vions. Thi rmltmegge's at tho GENT plow Rent is stbileod by «etal
Gea legen!

Ga desoptis. proveseee ave. been cumin ul previvosly by. mars
speckometry™ and HLULD! F echoigees, however the els ore mu,
‘onststeal, Ube wide cae of selivatin energie tpeetsa for Ga desorption goat
fom C4 e¥ fo 5d eee =, hile the. plelly roprted vals for GaN
ddeconnjothon ig near 35 6" The Ge dosorptor cozesce in the absence ct aa
eto niuogey thor wate tportsd to be 205 eV, 3.7 eV 3.1 eV and 22 eV fom
‘As (00017, GILSIC (GCF, Gute, aml Ca (O0DT) anvaces,sespecteey
‘Tie aiixence i. the Ga dezostion sng ecparted havo bron acebece tthe Ga
bond energy wits diecror bere atoms, fooee of cl rept al ie Ci,
ezorpiton exergy Som Gi (0CO1) setae nthe presence af RU i Tb OO
8, dancing Tw absuats temperate, tis suggoettht the aoarh easiramett
conditions modity ee desception enor. Th eBiect em the deserpticn roery by ta
enviuouneatel conditions is condraed by it dependence on the IY ro.
[ertermire oven the growth corel can allel he desrptnn ela Faces
‘ie Hionlsge thre har haan no senate anucy of Ga devevtion energy as &
Fanti of tis Ga surfece coverage. To hia work se analyze the desorpcon eS ws
{ fimetn af xe Ga coverage

Tn Us sly, celkcion high-uey eectou Uiliveton (REED) wax used
Ataing GS grow in PANTER wo eng te Ga deneption bohesior ends
‘its gconthoondiiens, Ths rerlte eveel a dependenos of desanpioneusigy af
{Gp om Gah surfice onthe Gn ayer coverage bch ts deerminet By the LL
sin, The desnyptin energy mas determined tobe 2.78 e under very Ga ih grote
Clin withthe la aslayer eorcrage close :o 100%, Thie vale iv clo Ta dhe
fnvaron exergy fie Ike ewapintin a0 Ga fiom seals Ga (ZAI eV"). With
decresing IY cao, the tesnisn enaeyy deeseand to O82 with coverage
tgs 10%. The diferent gra mes Erouphe aba by lle IL eatios
steak venga? and pared

“The experiments were cari ul usa pis silat MBE. in ceuipped
svi to convene Ci effin etfs forthe wt sposes and 8 adioequeasy
(Ar) plem some Kr Ue miropen (0001) GaN tec lens grow by metao-eenic
shemual veqr depociéan (MOCVD) on sapphire wero nsed as abst since hey
Trove wopiedusly see srtaces wth stomically fat teracee ‘Th: Cat epilayers
smote gry on tse abtales i the erpertie rouge of 6€8 °C ta FERC The a
[Bt RILACD operated al 159 Le, al vs Suet along tho [11-20] aimath oF te
GaN (Qt) eains wit a fod Mame: consne at LA easing iu Baad
cntision oument. The itsnste of REEED specular beam ws meni.oeed when the
fgemseh was seise. The deecmpticn exergy ws determina Gow tt aeatonsip
betwocu ho atnaiy aad mvbmtate rapture for giv IV rn. Vs study tho
pont aoe ander h(eeal cei, AP shat topology measurercuts ete
‘ied oul hich aged Che lavastigainn ofthe curfao morphology of GuX hich
{Bre guovcr op porout GaN template under ieent IN-W rates we the eubetate
fangranaea wan kee at 70°C.

‘Dusng the GaN prow MBE. a crim faction af autre sre Mux to
lium fx, iting lle wrTae neal a he bined fer afew, Wen Ga
Douce impioge on the GaN harps sortase, hay we sider isarsoratcd into Gok
plage ih active eigen or adsorbed onthe erfoe to firm layer 0 te
‘tier bare, somo Ga tom: may ve-evapoite Gum iby Ga ullyer. The Aesgpion
process becom patty wha le soba emgeetee i higher fn
$50 °C Tho incorortion,adcorpon axa deeespticn processes reich a siliaieat
‘ulcer GaN growth proceeds vader sey conn in which ase te
‘desorption ane oan be expressed

Eames EulhsT) 0
whet es the lll feo, Aba CAN roth tvepazatne by MBE (ae ie
in the rang: of 699 °C ~ 80D), the Ga adams docs not condense into u
‘entrain, fet rier seprzeat a quid He Hl," his reed lv eae an
fneatton ofthe RHEL speonlae bea intent” Ay a rca te degondones of
the desorption rain cepted hg the THERE imonsiy ve subsets temperate
provide ths ampecunty te stu tho dseortion kicetes of Gn in veel ine. We
Gromret the ssetionzhip besween the :ntzty of RULED a he devorptiva Urey
stn exponetta. even by

Temple)

2
at 9 cabs teepecanre T, wtb de

‘the Gy stnas deaueds Dus the sot
Gsnptin ete Ea

“Figace 7 shows the typcel wend of the vaviston of RIDEED specular beem
imenaly daring. GaN yeast vert imate eempeatuar under the
ickiowce coanne, Wa this #335, the Ga Boe ie sk:guty trgher then thal Lor
sivogen The Ga coll expert was lp coastal a 140° tbe pss
Sal Far, The sabtraly lerperaure was vivid fae 618 °C to 680 °C, Sco t's
feigeraine ange fe all, Hea be asuraed that the coverage change ofthe Git
dlayer oo GaN anor cate ty anerising subsite lempetaiare 18 Sophie