Tuyen tap bao cao khoa hpc Hfii nghi Khoa hpc ky thudt Do luting toan quo'c lan thfl IV Hd Ngi, 11-2005
SU PHAT TRIEN CUA CONG NGHE NANO VA N H O N G THACH T H U C M 6 | T R O N G U N H V U C C H E T A G T H I E T Bj DO LUdNG
Cung Tiianh Long
Trudng dgi hgc Bdch Khoa Hd Ngi, Khoa Diin, Bd mdn Ky thudt do vd Tin hgc cdng nghiep
Tdm tdt:
Bdi bdo dua ra mdt cdi nhin tdng quan ve cdng nghi nano vd nhiing hudng nghien cdu cdng nhu cdc kit qud dd dgt dugc trin mgt sdlTnh vitc. Bdng Ihdi bdi bdo ciing chi ra cdc thdch thdc mdi Irong linh vice che tgo Ihiel bi do ludng- phuang tiin khdm phd the gidi nano, mdt ITnh vitc hii sUc quan Irgng gdp phdn tgo nin nhOng ddt phd Idn trong cdng nghe nan.
Abstract:
This paper presents a review of nanolechnology and some research programs, as well as results of those programs. In addition, this paper also points to new challenges of the field of manufacturing instrumentation which used to discover nano world, a very important science field supporting to great successes in nanolechnology.
I. CONG NGHE NANO LA GI?
Ngufii ta dung khdi nifim cfing nghe nano di chi ITnh vuc khoa hpc vd cfing nghe ma dfi'i tupng nghien cflu cung nhu thao tdc cia nfi cfi kich thufic va dung sai trong ddi tfl 0,lnm tfii lOOnm. Vfii cfing nghe ndy, cho phip chi tao cdc thiit bi mfii dua trfin cdc tfnh chdt vat 1^ quen biit cia nguyen t i vd phan tfl. Nhttng thiit hi chi tao bdng cfing nghe nano cfi cdc dac tfnh sieu viet nhu nho hon, nhanh hon, bin hon hoac them nhiiu dac ti'nli hodn todn mfii so vfifi cdc thiit hi dupe chi tao tren nin tang cfing nghe hien nay.
Cfing nghe nano Id su kit tinh cia nhiiu thanh tuu khoa hoc trfin nhiiu linh vuc khdc nhau, vd la cfing nghe cfi tinh kha thi. Nhiiu nhd nghien cflu du bdo rdng cfing nghe nano se dem lai mfit cufic each mang mfii, md tiim nang flng dung cia nfi hifin nay mfii ehi dang dupe thao ludn & mflc dfi so khai.
II. CAC LiNH VUC TIEM NANG
Nhu chflng ta diu biit, cfing nghe hien tai cho phip ldm viec o kich thflfic micro cfin dflpc gpi la cfing nghe micro. Tren nin tang cia cflng nghe micro, chung ta chflng kiin cufic each mang vi cfing nghe thfing tin sau rfing, anh hufing tfii hdu khdp cdc ITnh vuc dfii sfing. Mfit dn tupng true quan rdt manh, dfi Id nang luc cia mdy tinh tdng theo hdm mu khi kich thflfic cdc linh kien giam theo hdm mfl. Tuy nhien, dfl bdo tfii nam 2015 hoac 2020 se la diem kit thuc cua cfing nghe silicon tinh khiit, khi md nfl luc thu nho kfch thufic cdc linh kien dat toi gioi han, o dfi cdc hifiu flng Iflpng tfl trfi nfin ddng ki lam mdt di tfnh ndng mong mudn cua chung. ^ *
Trong dai kfch co nano thi mpi tiip xuc vfii vdt thi bfin ngodi diu cfi thi ddn tfii nhung thay dfii trfin dac tinh eua dfii nrpng. Vi vay, bi mat tiip xuc trfi thanh mfit bai toan ion. Dai kich thuoc nano trong khoang tfl lO'm tfii 10'»m Id khoang chuyin tiip gifla vat
thi hod ddc va trang thai phdn tfi, cung la vung ma cdc hieu fing Iugng ifi trd nen dang kl.
Do dd, cac ddt phd tren ITnh vuc cdng nghe nano cd thi se din tfi ITnh vfic vdt ly lugng li, sinh hgc hay boa hgc.
Vdt ly lugng tfi dugc quan tdm nhilu do cd tiim ndng fing dung trong ITnh vuc vi dien tfi cd nano. Ngudi ta nghien cfiu phfiong phap tinh toan lugng tfi, phfiOng phap su dung trang thai cua cac nguydn tfi lam co sd tinh toan. Khdng gidng nhfi cac linh kien logic kinh diln ehl cd hai trang thai (0 va 1), cac nguyen tfi cd ba trang thai (0 hoac 1 hodc 01- xe'p chdng cua hai trang thai tren). Diiu nay dugc cac nhd Ihie'l ke' mach logic quan tdm, bdi nd md ra kha ndng xip chdng logic thdng qua mdt qua trinh vdt ly. Hien nay, cdc cdng lugng tfi don bit va da bit dang dfigc nghien cfiu cbl tao, dfing ky thudt bdy ion, song chfia dat nhilu tie'n bd. Khd khdn din tfi nguydn ly cua phuong phap nay, dd la thuc hien dieu khiln trang thdi cua nguyen tfi muc tieu dua tren trang thdi cua nguydn tfi diiu khiln, va phai dam bao gifi dugc su dn dinh cua he thdng theo thdi gian.
LTnh vuc truyin ihdng lugng tfi ciing duge quan tdm, trong dd truyin trang thai lugng tfi la phuong thfic da dfigc thf nghidm va cho thdy kha ndng fing dung Ihfic liln cao. Mdt cdch dl truyin trang thai lugng tfi Id sfi dung photon. "Vilt" trang thdi cua nguyen tfi len cdc photon rdi Iruyin chung di. 6 phia thu, nhung photon nay dugc dung dl vie't lai trang thdi tren eac nguyen tfi. Cdng nghe nay dang dugc nghien cfiu hoan thien dl cd thi che tao cac he thdng truyin thdng lugng tfi, kl ca vdn de ma hoa va sfia ldi truyin thdng tin.
Ngodi ra, vdt ly Ifiong tfi cdn hfia hen nhilu thdnh tuu khac trong ITnh vuc cdng nghe chi tao vdt lieu vd thi^t bi nano.
Sinh hgc dugc quan tdm d kha ndng tu td chfic va hodn thien. Nlu cd kha ndng phdn tich, ghi hinh dugc cdc qud trinh sinh hgc 6 cdp dd phdn tfi, chung ta se cd nhfing khdm pha mdd vl CO ehl luu gifi vd tdi tao thdng tin, cung nhu sfi dung sinh hgc dl cdi Ihidn co ch^ xfi 1;^ thdng tin,...
Trong ITnh vuc boa hgc, fing dung cd nhilu tiim nang id cbl tao mdy tinh phdn tfi.
Dilm ddc biet cua kiln trfic may tfnh dang nay la kha ndng chiu ldi cao. Ddy la mdt yeu cdu chinh y^u dd'i vdi mdy tinb phdn tfi, khi ma qui irinh san xudt d kfch thudc nhu vdy se ludn ludn tdn tai ldi. Them nOa, viec loai trfi nhflng ldi san xud't nay la vdn dl thuc su khd khdn va ddt dd.
III. M6T S6 THANH TUU NGHIEN ctiU cd BAN TRONG LINH VUC C6NG NGH$ NANO
Cd thi thd'y rdng nhiJng ddt pha vao thi gidi nano den tfi rd't nhilu hudng va md ra nhilu kha ndng fing dung hodn toan mdi la. Cdc nghien cfiu co ban hien nay tdp trung irong vdn dl xdy dung cdng nghd chi tao vdt lieu nano, nghidn cfiu cac tfnh chdt ly, hda cua vdt lieu nano, md dudng cho fing dung thuc tiln.
Ylu id cd tfnh chdt quylt dinh cho qua trinh phdt triin cdng nghe cua thi ky XXI la tim ra ky thudt cho phep ehl tao mdt each cd diiu khiln cdc mdu vat khdng gian ba chilu trong miln kfch diudc nano, vdi cdc ddc tfnh ly, hod mong mud'n. Ngudi ta da thanh cdng trong viec chu ddng bidn ddi cac tinh chdt dien, tfi va quang hgc ciia vdt chdt, thdng qua phuong phdp ldm biln ddi cd'u true nguyin tfi chd't rdn. Da co thi chuyin ddi mdt each cd kilm soat cac chd't each dien thanh ddn didn, chdt khdng tfi tfnh thdnh chd'l cd Ifi tfnh, thay ddi CO bdn cac ddc tinh quang hgc cua vdt lieu, bdng each loai bd cd chgn loc cdc nguyen tfi. Phfiong phdp loai bd co chgn Igc cac nguyen tfi cua mdt sd hc^ chd't rdn, vi vdy cd thi md ra mdt cdng nghe hit sfic cdn thie't cho nhilu bai loan nano chua cd ldi giai hien nay.
85
Nghien cflu tinh chdt cia vat lieu nano cung dang dflpc quan tam. Ngufii ta da phdt hien ra cac hieu flng quang ttt cue Ifin uen mfit sfi vdt lifiu ttt co cdu tnic nano, chu yiu trong cdc hpp kim. Hieu flng nay Ifin gdp 30 ISn so vfii cac vdt lieu tfl tfnh thfing thufing.
Nguon gfic cua hien tupng quang ttt cue Ifin hien chua dupe biit ro vd cac flng dung cua nfi cfin dang di ngo.
Hon nOa, de che tao cac thie't hi nano, khfing chi cdn tao ra cdc phdn tfl cfi nano, ma cfin phai bao dam dp tron mupt nguyfin t i uen bi mat cia chflng, dfing thai phai cfi kha nang tao ra cdc cau true nano 3D mfit each hoan toan diiu khiin dupe. Do dfi, dfi chi'nh xdc cia cdu trie nano thu hut dupe nhiiu nfi luc nghifin cflu. Ngufii ta da cfi thanh cfing mfii vi viec tao ra cac cau tnic nano va micro chi'nh xac - cdc cdu trflc nhdn tao fi trang thdi rSn- thue hien duoc vfifi nhiiu hinh ddng khdc nhau. Diiu nay la mfit thdnh cfing quan trpng.
Cling vfii kha nang tao ra cdc vdt lieu nano cfi ti'nh chdt nhu mong muon, chflng ta cfi thi chi tao cac thiet bj nano va micro tren qui mfl Ififn mfit each hodn todn chi dpng.
IV. THACH THUC vOl CAC THIET BI DO KHAM PHA THE Gl6l NANO Nhflng tiin bfi trong ITnh vuc nano cfin phu thufic vao cdc cfing cu do, phan tfch ddc tfnh vd quan sdt mfii tru&ng nano. Mufin phat triin vd xdy dung flng dung trfin cfing nghe nano phai thiit ki va lam chi dupe vific thiit ki cdc chfle ndng cho dfi'i tflpng nano. Di thdm dinh hoat dfing cua cdc vat lifiu nano mfifi, dac biet Id di cfi thi phdn tfch dupe tdt ca eac bufie chi tao vd chinh sfla, cdn cfi cac thie't bi do, cac cfing cu phdn tfch fi dai nano. Cdc vat lieu nano nhu fing nano cacbon, bdn ddn lai,... mufin dua vdo san xudt phai dupe tim hiiu chi'nh xdc trong dai kfch thufic nano va cfi dupe su hiiu bie't thdu dao vi tinh chat 1^, hod cua chflng. Khi cdc transistor, cac phdn tfl tfl tinh trong 6 cung may tfnh, cdc phdn tfl quang hpc trong cdc thiit bi quang,... thu nho tfii cfi hdng chuc nano met, khi giao dien gifla cdc thdnh phdn cd'u thanh san phdm giam xufi'ng cfi 1 nano met, thi viec xdc dinh hinh dang va thanh phdn hod hpc cua mfii nguyfin ti se trfi nen cd'p thiit hon dfi'i vfii qud trinh sdn xudt va hoat dfing cia thiit hi.
Chung ta diu biit, cdc thie't hi do lufin theo sau cdc tiin bfi vi cflng nghe, la thanh qua cia cdc tiin bfl vi cflng nghe. Nhung vfii thiit bi do, chung ta co cdc khdm phd di trufic, thue ddy phdt triin cfing nghe cho tuong lai. Do dfi, viec phdt triin cdc thifi't bi do cdn theo kip vfii su thay dfii nhanh chfing Uong Hnh vuc khoa hpc vd cfing nghe nano.
Tuy nhien, cho din nay chung ta chua phdt triin dupe cdc thiit bi do cho phip quan sdt Mnh anh cung nhu phan tfch dac tfnh ly hod cia vdt chdt fi cdp dfi nano. Hifin nay, chua cfi kha ndng xdc dinh dupe hinh ddng khfing gian ba chiiu cung nhu thanh phdn hod hpc tren mfit nguyen t i cua bdt ky mfit dfii tupng hay vat lifiu nao. Cdc hiin vi ddu do quit cho phep thiit lap hinh anh nguyfin tfl, do dflpc kiiu va vi tri cdc nguyen tfl, nhung chi dupe uen bi mat. Chung ta khfing cfi thfing tin dufii Ifip bi mat dfi. Ky thuat STEM (Scanning Transmission Electron Microscopy) sap ra dfii, cfi kha nang hieu chinh dung quang sai, hfla hen cfi dupe nhflng khdm phd tfi't hon, song ky thudt nay chi cfi thi nghien cflu cdc vdt heu fi thi rdn vfii kit cdu bin virng.
Trong linh vuc difin tfl nano hay vfii cac vat thi fi trang thai rdn, thdch thfle cia ky thuat do lufing nam fi viec xdc djnh dupe hinh dang khfing gian ba chiiu, tim ra cdc dac trung hoa hpc rieng biet vd chup hinh dupe cdu tao nguyen ti. Hon ntta, cfin cdn xac dinh dupe vi ni va mfii lifin he cua tdt ca cdc nguyen tfl, trong trang thdi hoat dfing cia dfii tupng. Chi khi cfi nhttng thfing tin chi'nh xdc vd hiiu rfi vdn di nay mfii cfi thi cfi nhflng dflt phd quan Upng trong cfing nghe chi tao cac thiet bi nano. Cdc ky thudt sfing ngdn, chum hat, hay hiin vi nguyfin tu neutral dang dupe nghien cflu di phat triin cdc thiit bi do cfi kha nang giai quyit dupe cac thdch thfle neu tren.
86
Vdi cac he thd'ng sinh hgc, khd khdn lai ndm 6 dilm la he thdng cd lien kit ye'u vd dl bi pha buy khi hdp thu ndng lugng. Trong khi dd, nhiem vu dat ra la phai ghi hinh dugc cac qua trinh chuyin ddi sinh hgc, Id'y hinh dugc protein don le, tfi luc nd hinh thanh cho tdi cdc tac ddng cua nd ddu dd tren te' bdo. Diiu nay ddi hdi cac thie't bi do phai cd dd phdn giai dudi Inm, ddng thdi khdng gdy anh hudng tdi dd'i tugng do. Do dd, cac thie't bi quang hgc vdn se la hudng uu tien. Hien nay, nhilu y kiln cho rdng, phat triin hien vi quang hgc don phdn tfi cung ky thudt giao thoa mdi, cd Ihl se la giai phap cho thdch thfic ndu tren.
Tdm lai, khoa hgc vd cdng nghe nano dang cd nhihig thanh cdng quan trgng, de'n lugt minh ky thudt do ludng cung cdn cd cac budc tie'n Idn, dii sfic khdm phd the gidi nano, lao da cho mdt cudc cdch mang cdng nghe thuc su irong luong lai.
Tdi lieu tham khdo:
1. Boris A. Gurovich. D.I. Dolgiy, E.P. Velihov, EZ. Meilikhov, E.A. Kuleshova, Selective removal of atoms for fabrication of nanostructures with desireable electric, magnetic and optical properties, Symposium and Summer School on Nano and Giga Challenges in Microelectronics - Research and Development Opportunities in Russia, Moscow, September, 2002.
2. Alexander B. Granovsky, Giant magnetooptical effects in nanostructured magnetic materials. Symposium and Summer School on Nano and Giga Challenges in Microelectronics Research and Development Opportunities in Russia, Moscow, September, 2002.
3. Victor Ya Prinz, New concept in fabricating building blocks for nanoelectronics and nanomechanics. Symposium and Summer School on Nano and Giga Challenges in Microelectronics Research and Development Opportunities in Russia,Moscow, September. 2002.
4. Paul Seidler .Nanolechnology and the information age. Symposium and Summer School on Nano and Giga Challenges in Microelectronics - Research and Development Opportunities. Cracow, September, 2004.
87
