國立中山大學學位論文典藏.doc

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慨郝
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3 : V

6 1-1

7 pattern V-grooves

10 (pattern transfer) µm 2500Å (SiO 2 ) µm

11 Abstract The objective of this thesis is to apply semiconductor etching process technologies on 6 inch P-type Si substrate and produce a mold of Light Guiding Plate (LGP). After evaporate chromium (Cr) onto the Si substrate as etch mask, the thin films were then patterned and subsequently etch by plasma. Different powers were used to compare the cross-sections of the patterns. The results would be the references of Si molding process. Another objective is to fabricate Si-V grooves which can connect the fibers and accurately position fibers. Anisotropic etching of Si-V grooves were formed using EDP solution, and sputtered Ta 2 O 5 was used as the etch mask. At a etching temperature of C, the under cut is 2.5~3µm. Additionally using SiO 2 as etch mask by thermo evaporation at 1050 Use EDP solution at C, the under cut is 2.25µm which had a better result.

Different powers were used to compare the cross-sections of the patterns. The results would be the references of Si molding process.

12 (MEMS) [1-4] 1950 [5] (isotropic etching) [6-9] (anisotropic etching) ( orientation- dependent etching )[10-13] [14] 1

13 (Si-molding) (Si-molding) (Si-molding) 2

14 a. (etch mask) b. (patterning transfer) c d. ( Cr ) ( Ti ) (SiO 2 ) (Si 3 N 4 ) (Ta 2 O 5 ) 5000Å pattern (a few mtorrs) 10-6 torr (CVD) pattern plasma etching Cr etch mask SF 6 /CHF 3 3

15 SF 6 CHF 3 [15] Ar V-grooves V-grooves V-grooves FTTH(Fiber To The Home) V-grooves AWG [16] V-grooves Ta 2 O 5 SiO 2 Ta 2 O Å Å SiO 2 BOE(Buffer Oxide Etch) EDP 110 4

AWG [16] V-grooves Ta 2 O 5 SiO 2 Ta 2 O 5

16 150cc/min V-grooves corner undercut(5-16) V-grooves Si molding Ta 2 O 5 SiO 2 V -grooves 5

17 1. 2. snell s law n sin θ = n' sin θ ' 3. : 2-1 6

18 250 Si-molding : ~ 100 µ m 40 µ m intensity intensity 2-2 pattern 7

19 ( ) 2-3 (a) (b) 2-3(a) (b) (Diffusion) (Boundary Layer) 8

20 2-4 CVD CVD Mass Transfer Diffusion Convection Bubble Ultrasonic Agitation 9

21 K.B.Been[6] EDP (ethylenediamine- pyrocatecol-water)[6;17]koh (postassium hydroxide-water)tmah (tetramethylammonium hydroxide)hydrazine-water CsOH (cesium hydroxide-water) EDPKOHTMAH 3-1 [20] 100 Si dangling bonds 10

22 Si conduction band Si Si OH Si : +2OH - Si + 2e - cond Si Si OH Si(OH) 2 Si-Si (backbones) Si(OH) 2 2- Si OH Si OH ++ Si Si + 2e - cond Si OH Si OH Si(OH) 2+ 2 Si(OH) 4 Si OH ++ Si + 2OH - Si(OH) 4 +Si solid Si OH PH Si(OH) 4 PH>12 Si(OH) 4 SiO 2 (OH) H + 2H + + 2OH - 2 H 2 O 11

23 4 H 2 O + 4e - 4 H 2 O - 4 H 2 O - 4 (OH) - + 2H 2 Si + 2(OH) H 2 O SiO 2 (OH) H EDP( ethylenediamine- pyrocatecol-water ) 1962 Crishal Harrington[18] hydrazine -pyrocatecol EDP Finne Klein[19] 2NH 2 (CH 2 ) 2 NH 2 + Si +3C 6 H 4 (OH) 2 2NH 2 (CH 2 ) 2 NH [Si(C 6 H 4 O 2 ) 3 ] H 2 KOH (postassium hydroxide-water) J.B Price alcoholic-koh [20] KOHH 2 O isopropyl alcohol(ipa) IPA KOH [21-22] : 12

24 Si + 2(OH) - Si (OH) e - 4 H 2 O + 4e - 4 OH - + 2H 2 Si (OH) OH - SiO 2 (OH) H 2 O TMAH (tetramethylammonium hydroxide) TMAH IC <130 Schnakenberg PH<13 (hillock)[23-24] CH 3 + TMAH CH 3 N CH 3 OH CH diamond cubic crystal <111> <100> <110> <110><100><111> <100><111> U (111) <110> V

25 2-5 Si <110> <100> <111> [100] θ=54.74 [110] [111] 14

26 Cr 15

27 : 1.? 9? 10 2.?? 9? 10 3.?? 9? ,? 120 C 30 : 1. (Thermo-evaporation) (Cr) : a. : 5x10-6 torr b. : 75 c. : 0.4~0.5 Å/sec ( ) d Å ~4000 Å Å/sec ( ) 16

28 : 1. Laurell WS-6NPP a rpm 10 b rpm 40 6 AZ a. I-line 42 b. DI water AZ400K 4:1=600cc:150cc c. DI water Si Photoresist Cr

29 : () Cr7 : 400cc Cr7 Cr7 (over-etching) 50Å /sec Si Photoresist Cr 3-2 : Cr mask 1.Actone (Cr) 2.IPA DI water 3. 4.Dektek Si Cr

30 : Plasma SF 6 /CHF 3 Electron Cyclotron Reaonance(ECR) (plasma) Reactive Ion Etching(RIE) 6~10µm Ar plasma etching patterns sample O 2 : RIE: 200W torr : 15mtorr RIE ECR 1. SF 6 : s.c.c.m CHF 3 : 2.5 s.c.c.m Ar : s.c.c.m torr 8 mtorr 2. a. RIE/ECR=200/150 W 25 : /min 19

31 b. RIE/ECR=150/150 W 25 : /min c. RIE/ECR=100/150 W 25 : /min d. RIE/ECR=50/150 W 27 : /min : ( Cr ) Cr 7 10~15 20

32 3-4 SF 6 /CHF 3 Si substrate Cr etch mask Etched patterns Residual Cr etched mask Ar + Patterns bottom Protect Si from bombardment Completed patterns 21

33 : 1cm sample : SiC rpm pattern :

34 : pre-plating coating : 1. Laurell WS-6NPP spin coater 2. AZ : : 8.5cm patterns 6cm : AZ-400 4:1 6. :

35 : 1.5mm : e-beam : Acetone Acetone pre-plating coating : NMP AcetoneIPA DI water 24

36 : NMP 3-1 : Acetone IPA DI water Laurell WS-6NPP rpm 4000rpm 25

37 pattern undercut 1 8.5cm 26

38 EDP SiO 2 Ta 2 O 5 : SiO 2 : 1050 Å SiO 2 : 1.? 1? 10 2.? 1? 10 3.?? 1? ,? 120 C 30 27

39 : 1. HMDS Laurell WS-6NPP a. HMDS b. AZ4210 : 1500 rpm rpm 40 c. : <110> 3. I-line 42 DI water AZ400K 4:1 DI water 28

40 4. : : AZ4210 pattern SiO 2 : : SiO 2 BOE(Buffer Oxide Etch) BOE (NH 4 F) (HF) 40% (NH 4 F) 49% 10 BOE : c.c.DI water 180c.c. 20c.c 49 BOE SiO 2 sample BOE 29

41 : EDP V EDP : 4-1 Si Si P.C(C 6 H 6 O 2 ) 45 g H 2 O 120 c.c. EDA(NH 2 CH 2 CH 2 NH 2 ) 255 c.c. : EDP :110 :0.88µm/min 30

42 4-1 SiO 2 1. SiO 2 Si SiO 2 SiO 2 2. Si Photoresist SiO 2 SiO 2 3. Si Photoresist SiO 2 SiO 2 4. Photoresist SiO 2 Si SiO 2 Photoresist 31

43 5. SiO 2 BOE Photoresist SiO 2 Si SiO 2 Photoresist 6.Acetone SiO 2 Si SiO 2 7.EDP Si SiO 2 Si SiO 2 32

44 Ta 2 O 5 : : Ta 2 O 5 Si 4500Å Ta 2 O cm 22 : 1. : 80 W 2. : 3 mtorr 3.Ar : 17.5 s.c.c.m 4. : Å /min.... Ta 2 O 5 Si 5750µm Ta 2 O 5 : 1. :80 W 2. : 0.7 mtorr 3.Ar : 7.5 s.c.c.m 4. : 32 Å /min 33

45 . Ta 2 O 5. EDP V EDP : Si P.C(C 6 H 6 O 2 ) 45 g H 2 O 120 CC EDA(NH 2 CH 2 CH 2 NH 2 ) 255 CC : : 1.09µm/min 1. Ta 2 O Ta 2 O 5 Si Ta 2 O 5 34

46 2. Photoresist Si Ta 2 O 5 3. Ta 2 O 5 Ta 2 O 5 Si Ta 2 O 5 4. Ta 2 O 5 Ta 2 O 5 Si Ta 2 O 5 Ta 2 O 5 Si Ta 2 O 5 35

47 Si V-grooves alignment <110> undercut <110> <110><-110> 4-3 <110> SiO 2 (HF) SiO 2 3 BOE(Buffer Oxide Etch) 49%HF - 40%NH 4 F 10% 13Å/secBOE 36

48 120 1hr SiO BOE Ta 2 O 5 Alignment EDP 37

49 Si molding EDP : Si molding ECR (Electron Cyclotron Resonance) 150 RIE (Reactive Ion Etch) /min0.250 /min0.245 /min0.23 /min RIE pattern undercut RIE RIE Si Ar

50 5-8 RIE=200WECR=150W SF 6 : s.c.c.mchf 3 : 2.5 s.c.c.mar : s.c.c.m Si molding φ lm(lumen) φω Luminance(cd/m 2 ) φ Ω θ θ θ 39

51 5-1 RIE/ECR=200/ RIE/ECR=150/150 40

52 5-3 RIE/ECR=100/ RIE/ECR=50/150 41

53 5-5 Si Ar 5-6 Si 42

54 pattern 5-8 pattern 43

55 Si V-grooves EDP 1 400cc 20 (111) concave undercut(5-10) (111) ( 5-11) c.c.EDP V-grooves SEM V-grooves Ta 2 O 5 undercut 2.5~3 undercut 5-12 (lift off) Ta 2 O 5 EDP SiO 2 EDP undercut ) SiO 2 EDP BOE corner undercut Si V-grooves 44

56 45

57 5-9 BOE cc EDP concave undercut 46

58 5-11 (111) 5-12 Ta 2 O 5 47

59 SiO 2 EDP undercut 5-14 V 48

60 corner undercut 49

61 50µ 250µ 5-17 V-grooves 5-18 V-grooves 50

62 c.c.EDP 5-20 EDP 51

63 Si molding RIE=200WECR=150W ; Si molding V-grooves Ta 2 O µm/minundercut 2.5~3µm 210µm 148.5µm 2.38%~2.86% SiO µm/minundercut 2.25µm 200µm 141.5µm 2.25% undercut 52

64 1. Gregory T.A. Kavacs, Nadim I. Maluf, and Kurt E. Peterson, Bulk Micromachining of Silicon, Proceedings of the IEEE, Vol.86, Aug 1998, p Walter Lang, Silicon microstructuring technology,materials Science and Engineering,R-reports,Vol.17,Iss.1,pp1-55, Gregory T.A. Kavacs, Kurt Peterson, Michael Albin, Silicon Micromachining Sensors to Systems, Analytical Chemistry News& Features, pp ,july 1, Kurt E. Peterson, Dynamic Micromechanics on Silicon: Techniques and Devices, IEEE Transactions on Electron devices,vol 25, No.10, pp , D.B.Lee, Anisotropic Etching of Silicon, J.Appl.Phys.,Vol.40,1969, p K.D.Been, Anisotropic Etching of Silicon, IEEE Trans. Electron Devices,Vol.ED-25, 1978,p Lj.Ristics, CMOS Technology A Base for Micromachining, Microelectronics J.,Vol 20,1989, p R.M.Finne and D.L Klein, A Water Soluble Amine Complexing Agent System for Etching Silicon, J.E.C.S.,Vol.114,19,1967,p D.L.Kendall, Vertical Etching of Silictchingon at Very High Aspect Ratios, Ann. Rev.Mater.Sci.,9,1979,p H.Seidel,L.Csepregi, A. Heuberger and Baumgartel, Anisotric Etching of Crystalline Silicon in Alkaline Solution-I. Orientation Dependence and Behavior of Passivation Layer, J. of Electronchem. Soc., Vol.137, 1990,p M.Elwinspoek, On the Mechanism of Anisotropic Etching of Silicon, J.Electrochem.Soc.,140,p M. Elwinspoek et al., Wet Chemical Etching Mechanism of Silicon, IEEE International Workshop on Micro Electro Mechanical Systems, MEMS 94,Oiso, Japan,p.223-8, D. Zielke, J.Fruhauf, Determination of Rate for Orientation Dependent Etching, Sensors and Actuators A 48 (1995),p Walter Lang, Silicon Microstructure Technology, Material Science an Engineering, R17(1996),p R. Hsial and J. Carr, Si/SiO2 etching in high density SF 6 /CHF 3 /O 2 plasma, Materials science and Engineering B, pp ,

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2 Miller Index (hkl) (1 00) X {hkl} {100} (100),(010),(001),(100),(0 10),(00 1) [hkl] (hkl) [100] (100) <hkl> 3 Characteristics of Etching Techniques

2 Miller Index (hkl) (1 00) X {hkl} {100} (100),(010),(001),(100),(0 10),(00 1) [hkl] (hkl) [100] (100) <hkl> 3 Characteristics of Etching Techniques 1 National Kaohsiung First University of Sci. & Tech. Silicon Anisotropic Wet Etching Department of Mechanical and Automation Engineering National Kaohsiung First University of Science and Technology MicroSystem