1
2
3
4
5
6
(a) (b) 7
8
9
10
B+B B E 2 D Energy Molecular state B 2 Dissociated state Distance from the surface 11
Deposition Rate 1 Monolayer Saturation Point Source Pulse Time Thickness Cycle Number 12
Deposition Rate 1 Monolayer Process Window Temperature 13
14
15
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17
18
19
20
21
22
23
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Gas flow mechanism Laminar flow Shower-Head Injector A,Ar,B A,Ar,B Structure A,Ar,B Advantages 1. High Material utilization efficiency. 2. Minimization of reaction volume. 1. Uniform source flux offered 1. Simplified structure offers easier purge and easy maintenance. 2. No source depletion over large area substrate. Dis - advantages 1. Thickness non-uniformity due to source depletion at inlet area makes it unsuitable for large area deposition. 2. Complex reactor structure 1. Relatively large purging time due to large reaction volume and low conductance of showerhead holes make it difficult to realize pure ALD system. 1. Minimization of reaction volume is needed for better material utilization efficiency. [A,B = Reactants. Ar = Argon (inert gas for purging)] 26
TMA Purge-Ar O 3 Purge-Ar on on on on on on 1 Cycle 27
Parameter Condition Source Oxidant O 3 : ozone Purging Gas Ar Process pressure 400~600 mtorr Substrate Si(100) Process temperature 350-400 28
29
140 120 Thickness(A ) 100 80 60 40 20 0 0 20 40 60 80 100 120 140 160 Number of cycles 30
200 Thickness (A ) 160 120 80 40 20 10 Uniformity (%) 8 6 4 2 0.0 0.5 1.0 1.5 2.0 2.5 3.0 TMA step time (sec) 31
32
Uniformity (%) Thickness (A ) 90 80 70 60 50 40 5.0 4.0 3.0 2.0 (b) (a) (b) (a) 1.0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 Oxidant step time (sec) 33
Growth rate (A / cycle) 1.0 0.8 0.6 0.4 0.2 (a) (b) 200 250 300 350 400 450 Growth Temperature ( o C) 34
100 90 Si 80 Atomic Concentration(%) 70 60 50 40 30 20 10 O Al C 0 0 2 4 6 8 10 12 14 Sputter Time(min.) 35
Normalized yield 3000 2500 2000 1500 1000 O He + Al 15 o Al 2 O 3 Si 500 0 200 300 400 500 600 700 800 Channel 36
Al 2p H 2 O Al 2p O 3 Intensity (a. u.) (a) (b) 68 72 76 80 84 O 1s H 2 O 66 70 74 78 82 O 1s - O 3 Intensity (a. u.) (c) (d) 526 530 534 538 524 528 532 536 Binding energy (ev) 37
38
Al 2 O 3 Poly Si 39
40
41
42
43
44
45
1 cycle TiCl 4 Ar NH 3 A B Substrate B A B A 1cycle Ar Time 46
47
Deposition Rate (Å/min) 100 90 80 70 60 50 40 30 20 10 0 360 380 400 420 440 460 480 500 Temperature ( o C) 48
Resistivity (µω) 900 800 700 600 500 400 300 200 100 360 380 400 420 440 460 480 500 Temperature ( o C) 49
500 450 400 350 Thickness(nm) 300 250 200 150 100 50 0 0 100 200 300 400 500 600 700 800 900 Cycle Number 50
5000 4000 3000 2000 1000 0 500 400 30 40 50 60 70 80 375 51
52
100 90 Atomic concentration(%) 80 70 60 50 40 30 20 10 N C Cl O Ti Si O 0 0 2 4 6 8 10 Sputter time(min) 53
60 N 50 O Si Atomic Concentration (%) 40 30 20 Cl : 1.23% Cl Ti 10 0 0 2 4 6 8 10 Sputtering Time (min.) 60 N Atomic Concentration (%) 50 40 30 20 Cl : 0.38% O Si Cl Ti 10 0 0 2 4 6 8 10 Sputtering Time (min.) 54
55
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감사의글 갑신년한해가밝았습니다. 올해는제게뜻깊은한해가될것같습니다. 10년동안의학생신분에서사회인신분으로, 20대에서 30대로, 제자신의미래를진지하게생각해볼때인것같습니다. 처음청운의꿈을안고대학원에들어와이제 2년여동안의대학원생활을마치려합니다. 뒤돌아보면아쉬운점이많이남습니다. 제가대학원에들어올수있었던것은행운이었습니다. 여러사람들과만나제자신을돌아볼수있었고많은경험과함께좀더성숙할수있었던기회였습니다. 우선, 언제나한결같은웃음으로작은일에도칭찬을아끼시지않으셨던이종무교수님께진심으로감사드립니다. 그리고연구실에서같이생활했던많은선후배분들과친구들이저에게는많은도움이되었습니다. 우리연구실에기둥이자분위기메이커였던종민형, 처음대학원에들어올때부터동거동락한착한마음을가진덕렬과멋지고똑똑한태종에게고마움을전하고싶습니다. 그리고우리가졸업한후에도연구실의리더로써잘이끌승모, 항상동병상련의아픔을같이했던 5북라인퀸가현아, 연구실의브레인경철에게도고마움을전합니다. 많은생활은하지않았지만옆자리에서묵묵히열심히일하는대규, 항상걱정스러운대교, 믿음직스러운연구실의막내충모와연규, 다른연구실이지만한가족같이지냈던남호그리고졸업한선배들, 제가대학원에서일하는데많은도움을준진중형, 우리 leg의맏형재범형, 취업에많은도움을주고제가믿고따르는광표형, 똑똑한균석, 벌써결혼해서유부남이된한승, 광식또한대학원생활동안많은도움을줬던친구들원휘, 정열, 문갑, 우정, 기홍에게고맙다는말을전하고싶습니다. 생각하면할수록감사할분들이너무나많은것같습니다. 마지막으로지금의제가있기까지부모님과누나에게이논문을바칩니다. 저에게아낌없는격려와지원을해주신 2004 년홍현석 62