Mfundo yaikulu ya vacuum evaporation ❖ kuyanika
1, Zida ndi njira zakuthupi za vacuum evaporation ❖ kuyanika
Zipangizo zophikira mpweya wa vacuum zimapangidwa makamaka ndi chipinda chopopera mpweya ndi makina otulutsira mpweya. Mkati mwa chipinda chopopera mpweya, muli gwero la mpweya wa evaporation (monga chotenthetsera mpweya wa evaporation), chimango cha substrate ndi substrate, chotenthetsera cha substrate, makina otulutsa utsi, ndi zina zotero.
Chophimbacho chimayikidwa mu gwero la evaporation la chipinda chopanda mpweya, ndipo pansi pa mikhalidwe yokwera ya vacuum, chimatenthedwa ndi gwero la evaporation kuti chisanduke nthunzi. Pamene kuchuluka kwa mamolekyu a nthunzi kuli kwakukulu kuposa kukula kwa mzere wa chipinda chopanda mpweya, maatomu ndi mamolekyu a nthunzi ya filimu atatuluka pamwamba pa gwero la evaporation, nthawi zambiri salepheretsedwa ndi kugundana kwa mamolekyu ena kapena maatomu, ndipo amafika mwachindunji pamwamba pa substrate kuti apake. Chifukwa cha kutentha kochepa kwa substrate, tinthu ta nthunzi ya filimu timazungulira pamwamba pake ndikupanga filimu.
Pofuna kukonza kumatirira kwa mamolekyulu ndi substrate, substrate ikhoza kuyatsidwa ndi kutentha koyenera kapena kuyeretsa ma ion. Chophimba cha vacuum evaporation chimadutsa munjira zotsatirazi zakuthupi kuyambira kutha kwa zinthu, kutumizidwa mpaka kuziyika mu filimu.
(1) Pogwiritsa ntchito njira zosiyanasiyana zosinthira mitundu ina ya mphamvu kukhala mphamvu yotentha, filimuyo imatenthedwa kuti inyowe kapena kusandulika kukhala tinthu ta mpweya (maatomu, mamolekyulu kapena magulu a atomu) ndi mphamvu inayake (0.1 mpaka 0.3 eV).
(2) Tinthu ta mpweya timachoka pamwamba pa filimuyo ndipo timapita pamwamba pa substrate pa liwiro linalake la kuyenda, makamaka popanda kugundana, molunjika.
(3) Tinthu ta mpweya timafika pamwamba pa substrate timagwirizana ndi nucleate, kenako timakula kukhala filimu yolimba.
(4) Kukonzanso kapena kugwirizana kwa maatomu omwe amapanga filimuyi.
2、Kutentha kwa nthunzi
(1) Kukana kutentha kotentha
Kukana kutentha ndi njira yosavuta komanso yogwiritsidwa ntchito kwambiri yotenthetsera, yomwe imagwiritsidwa ntchito kwambiri pazinthu zokutira zokhala ndi malo osungunuka pansi pa 1500℃, zitsulo zokhala ndi malo osungunuka kwambiri mu mawonekedwe a waya kapena pepala (W, Mo, Ti, Ta, boron nitride, ndi zina zotero) nthawi zambiri zimapangidwa kukhala mawonekedwe oyenera a gwero la evaporation, lodzaza ndi zinthu zosungunuka, kudzera mu kutentha kwa Joule kwa magetsi kuti asungunuke, asungunuke kapena asungunuke zinthu zopaka, mawonekedwe a gwero la evaporation makamaka amaphatikizapo multi-strand spiral, U-shaped, sine wave, thin plate, boat, cone basket, ndi zina zotero. Nthawi yomweyo, njirayo imafuna kuti zinthu zoyambira evaporation zikhale ndi malo osungunuka kwambiri, kupanikizika kochepa kwa nthunzi, mankhwala okhazikika, osakhala ndi mankhwala ndi zinthu zophimba kutentha kwambiri, kukana kutentha bwino, kusintha pang'ono kwa mphamvu, ndi zina zotero. Imagwiritsa ntchito mphamvu yayikulu kudzera mu gwero la evaporation kuti ipangitse kutentha ndikusanduka nthunzi ya filimuyo potenthetsera mwachindunji, kapena kuyika zinthuzo mu crucible yopangidwa ndi graphite ndi zitsulo zina zosagwirizana ndi kutentha kwambiri (monga A202, B0) ndi zinthu zina kuti kutentha kosalunjika kusweke.
Chophimba chotenthetsera chokana kupopera madzi chili ndi zoletsa: zitsulo zokana kupopera madzi zimakhala ndi mpweya wochepa, zomwe zimakhala zovuta kupanga filimu yopyapyala; zinthu zina zimakhala zosavuta kupanga alloy ndi waya wotenthetsera; sikophweka kupeza kapangidwe kofanana ka filimu yosakanikirana. Chifukwa cha kapangidwe kake kosavuta, mtengo wotsika komanso kugwiritsa ntchito mosavuta njira yotenthetsera yokana kupopera madzi, ndi njira yofala kwambiri yogwiritsira ntchito njira yotenthetsera madzi.
(2) Kutenthetsa kwa electron beam evaporation
Kutuluka kwa mpweya wa ma elekitironi ndi njira yotulutsira nthunzi ku zinthu zokutira poziphulitsa ndi mpweya wa ma elekitironi wochuluka mphamvu poziyika mu chophikira cha mkuwa chozizira ndi madzi. Gwero la nthunzi limapangidwa ndi gwero lotulutsa ma elekitironi, gwero la mphamvu yofulumira ya ma elekitironi, chophikira (nthawi zambiri chimakhala chophikira cha mkuwa), chophikira cha maginito, ndi malo oziziritsira madzi, ndi zina zotero. Mu chipangizochi, zinthu zotenthedwa zimayikidwa mu chophikira chozizira ndi madzi, ndipo mpweya wa ma elekitironi umaphulitsa gawo laling'ono kwambiri la zinthuzo, pomwe zinthu zambiri zotsalazo zimakhalabe pa kutentha kochepa kwambiri pansi pa mphamvu yozizira ya chophikira, chomwe chingawonedwe ngati gawo lophulika la chophikira. Chifukwa chake, njira yotenthetsera mpweya wa ma elekitironi kuti utuluke ingathe kupewa kuipitsidwa pakati pa zinthu zokutira ndi zinthu zoyambira kuuluka.
Kapangidwe ka gwero la evaporation la electron beam kangagawidwe m'mitundu itatu: mfuti zolunjika (Boules guns), mfuti zozungulira (zosinthidwa ndi magetsi) ndi mfuti zamagetsi (zosinthidwa ndi maginito). Chotsukira chimodzi kapena zingapo zitha kuyikidwa pamalo osinthira evaporation, zomwe zimatha kusungunuka ndikuyika zinthu zambiri zosiyanasiyana nthawi imodzi kapena padera.
Magwero a evaporation a electron beam ali ndi ubwino wotsatirawu.
①Kuchuluka kwa kuwala kwa ma elekitironi komwe kumatuluka kuchokera ku evaporation source kumatha kukhala ndi mphamvu zambiri kuposa mphamvu yotenthetsera yomwe imateteza kutentha, zomwe zimatha kuwononga zinthu zomwe zimasungunuka kwambiri, monga W, Mo, Al2O3, ndi zina zotero.
②Chophimbacho chimayikidwa mu chophikira chamkuwa choziziritsidwa ndi madzi, chomwe chingapewe kuuma kwa zinthu zomwe zimachokera ku utsi, komanso momwe zimachitikira pakati pawo.
③Kutentha kumatha kuwonjezeredwa mwachindunji pamwamba pa zinthu zokutira, zomwe zimapangitsa kuti kutentha kukhale koyenera kwambiri komanso kutayika kwa kutentha ndi kutentha kukhale kochepa.
Vuto la njira yotenthetsera ya elektron beam evaporation ndilakuti ma elekitironi oyambira ochokera ku mfuti ya elekitironi ndi ma elekitironi ena ochokera pamwamba pa zinthu zokutira adzapangitsa ma atomu omwe akutuluka ndi mamolekyu a mpweya wotsala kukhala ioni, zomwe nthawi zina zimakhudza ubwino wa filimuyi.
(3) Kutentha kwamphamvu kwambiri komwe kumayendetsedwa ndi ma frequency ambiri
Kutenthetsa kwamphamvu kwambiri (High-frequency induction heating evaporation) ndiko kuyika chotenthetsera ndi zinthu zokutira pakati pa chotenthetsera champhamvu kwambiri, kotero kuti zinthu zokutirazo zipange mphamvu yamphamvu ya eddy current ndi hysteresis pansi pa kulowetsedwa kwa mphamvu yamagetsi yamphamvu kwambiri, zomwe zimapangitsa kuti filimuyo itenthe mpaka itasungunuka ndi kuuma. Gwero la kuuma nthawi zambiri limakhala ndi chotenthetsera champhamvu choziziritsidwa ndi madzi ndi chotenthetsera cha graphite kapena ceramic (magnesium oxide, aluminium oxide, boron oxide, etc.). Mphamvu yamagetsi yamphamvu kwambiri imagwiritsa ntchito ma frequency a 10,000 mpaka 100,000 Hz, mphamvu yolowera ndi ma kilowatts angapo mpaka mazana angapo, kuchuluka kwa zinthu za nembanemba kukakhala kochepa, kuchuluka kwa kulowetsedwa kumakhala kwakukulu. Kuchuluka kwa kulowetsedwa kwa chotenthetsera nthawi zambiri kumapangidwa ndi chubu chamkuwa choziziritsidwa ndi madzi.
Kuipa kwa njira yotenthetsera yotenthetsera yothamanga kwambiri ndikuti sikophweka kusintha mphamvu yolowera, ili ndi zabwino zotsatirazi.
①Kuchuluka kwa nthunzi
② Kutentha kwa gwero la nthunzi kumakhala kofanana komanso kokhazikika, kotero sikophweka kupanga chodabwitsa cha madontho opaka utoto, ndipo chingapewenso chodabwitsa cha mabowo ang'onoang'ono pa filimu yosungidwa.
③Magwero a nthunzi amadzazidwa kamodzi kokha, ndipo kutentha kumakhala kosavuta komanso kosavuta kuwongolera.
Nthawi yotumizira: Okutobala-28-2022