MEMS fabrication process and its application to nanotechnology

(1)

台灣師範大學機電科技學系 -1-

微機電製程技術與其在奈米科技之應用微機電製程技術與其在奈米科技之應用

MEMS fabrication process and its application to nanotechnology

楊啟榮博士

副教授

國立台灣師範大學機電科技學系

Department of Mechatronic Technology National Taiwan Normal University

Tel: 02-23583221 ext. 14 E-mail:[email protected]

台灣師範大學機電科技學系 C. R. Yang, NTNU IMT

綱綱要要

z

微機電系統技術的重要性

z

微機電製程技術

—

矽基微加工 vs. 非矽基微加工技術

z

微機電製程在奈米科技之應用

—

微反應器應用於量子點合成之研究

z

結論

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-3-

根據興趣專長選擇研究方向

z

Optical MEMS

z

Bio-MEMS

z

RF-MEMS

z製程、元件、封裝..

分析模擬與最佳化設計軟體

z

ANSYS

z

CoventorWare

z

IntelliSuite

z

MEMS Pro

z計算流體力學軟體(CFD) z

……

可支援單位

z自有實驗室

z國實院高速電腦中心

z國科會北中南NEMS中心 z工研院各所

z中科院五所

z個別教授研究室

z私人公司

z

……

元件光罩圖案(Layout) 設計軟體

z

CADENCE

z

L-EDIT

z

AUTOCAD

z

……

轉檔成GDS格式 送件光罩製作單位

z交大奈米中心

z 國家奈米元件實驗室 z台灣光罩

z新台科技

z膠片光罩……

製程、封裝、檢測可支援單位

z自有實驗室

z國科會北、中、南NEMS中心 z國家奈米元件實驗室(NDL) z國實院儀器科技研究中心(ITRC) z國家同步輻射研究中心(NSRRC) z國實院晶片系統設計中心(CIC) z交通大學奈米中心

z 國科會貴儀中心 z工研院各所 z中科院五所 z個別教授研究室 z私人公司

zMUMPs代工(國外)

zMPMC代工 (中區NEMS中心) z

……

MEMS MEMS領域研究流程圖

領域研究流程圖

微機電系統技術的重要性微機電系統技術的重要性 ( I ) ( I )

z

超「輕、薄、短、小」

z

高附加價值

z

符合環保、省能源

z

省空間、省材料等實現產品以下之優點：

實現產品以下之優點：

質譜儀

70 Kg, 30000 cm³, 1200 W Europa Scientific, UK

微質譜儀晶片

0.2 Kg, 3 cm³, 0.5 W DARPA, USA 微機電系統技術

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整合感測器、致動器及電子電路的微機電元件整合感測器、致動器及電子電路的微機電元件

感測器

sensors

致動器

actuators

電子電路

circuits

微結構

microstructure

致動器

actuators

驅動迴路

driver

力感測器

force sensor

電子電路

circuits

雷射偵測器

laser detector

訊息控制迴路

communication

微機電系統名稱分類與應用領域微機電系統名稱分類與應用領域

美國：Micro-Electro-Mechanical System (MEMS) 日 本：Micromachines

歐洲：Micro-Systems Technology (MST)

MEMS applications:

-

Optical MEMS (光學應用)

MOEMS: Micro Opto Electro Mechanical Systems MOMS: Micro Opto Mechanical Systems

-

Bio MEMS (生化醫學應用)

μTAS：Micro Total Analysis System LOC：Lab. On a Chip

-

RF MEMS (無線通訊應用)

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-7-

Source: NEXUS III, http://nexus-mems.com/

*Other are: microreaction, chip cooler, MEMS memories, liquid lenses, microspectrometer, wafer probes, micro-mirrors for optical processing, micro-pumps, micromotors, chemical analysis systems

奈米碳管奈米碳管

AFM探針 AFM

探針

H. Dai et al., Nature 384, 147, 1996.

微機電技術是奈米科技跨入應用的橋樑微機電技術是奈米科技跨入應用的橋樑…………

微機電系統技術的重要性

微機電系統技術的重要性 ( II ) ( II )

(5)

探探針針陣陣列列

探針陣列可做平行式掃描，大幅提昇掃描速度，並可應用於大面 積加工。(左: http://www.stanford.edu/group/quate_group;右:

http://www.almaden.ibm.com)

探針陣列於奈米硬探針陣列於奈米硬

碟之應用碟之應用

http://www.almaden.ibm.com

IBM奈米硬碟千足計畫(Millipede project)

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微機電製程技術微機電製程技術

基礎IC 基礎 IC製程技術製程技術

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國家奈米元件實驗室 http://www.ndl.org.tw

半導體積體電路製程介紹碟片半導體積體電路製程介紹碟片

薄膜沉積薄膜沉積

Chemical Vapor Deposition (CVD)

Chemical Vapor Deposition (CVD)

z

PECVD

z

LPCVD

z

APCVD

z

MOCVD

(光電薄膜沉積)

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-15-

Sputtering Sputtering

Physical Vapor Deposition (PVD) Physical Vapor Deposition (PVD)

Joule heat or Electron beam Joule heat or Electron beam

基板

光罩光阻紫外光曝光

薄膜

基板基板

薄膜

正光阻顯影負光阻

薄膜

基板薄膜

蝕刻

薄膜基板

基板薄膜

光阻去除

薄膜基板

正、負光阻微影製程示意圖

黃光微影製程

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光阻的微影程序光阻的微影程序

Dehydration Bake

resist resist

Vacuum Spin Coating

Soft Bake

Exposure UV

Post Exposure Bake

Vacuum Spin Drying

Hard Bake 10-15min @ 250℃

(optional)

? min @ ?℃

? dosage/?thickness Development

(agitation)

? min @ ? ℃

(Rinse)

(Priming)

濕式蝕刻法乾式蝕刻法

溼式與乾式蝕刻溼式與乾式蝕刻

電漿

蝕刻遮罩層結構層

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Cr-7

熱製程熱製程

熱氧化處理需要在高溫爐管區中進行，爐內溫度控制在800 - 1000℃。矽晶圓在爐內高 溫環境下，晶圓表面會與通入爐管內之氧氣作用而形成二氧化矽膜(SiO₂

)。

氧化矽成長氧化矽成長

SiO₂

Si

(a) 熱氧化成長SiO₂

(b) 微影及BOE蝕刻SiO₂

Si SiO₂ PR

Si

(c) TMAH蝕刻液中以不同操作條件蝕刻 SiO₂

氧化矽作為蝕刻遮罩氧化矽作為蝕刻遮罩

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NMOS PMOS

離子摻雜(doping)離子摻雜

(doping)的目的

的目的

擴散法

擴散法(diffusion)(diffusion) 離子植入(Ion implantation)

離子佈植是將所需的摻雜元素(如砷)電離成正離子，並施加高偏壓，使其獲得一定的動能，以高速射入矽晶圓的技術。

擴散時摻雜物質經由氣體帶入爐管中，藉由一定時間的高溫擴散，擴散為所需的濃度分佈曲線。

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substrate resist

(a) Define resist

(b) Metal deposition

Metal source

Acetone

(c) Strip resist

掀離法製作金屬圖案技術掀離法製作金屬圖案技術

Construction of metallization patterns by life

Construction of metallization patterns by life- -off process off process

矽基微加工技術矽基微加工技術

z

面型矽微加工面型矽微加工

(Surface micromachining) (Surface micromachining)

z z

體型矽微加工體型矽微加工

(Bulk micromachining) (Bulk micromachining)

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(必須放在最後步驟)

Process Flow

Process Flow of Surface Micromachining of Surface Micromachining Sacrificial layer release by selective etching Sacrificial layer release by selective etching

Process Flow

Process Flow of Surface Micromachining of Surface Micromachining

Sacrificial

Sacrificial Floating Floating

Poly-Si

SiO

₂

BOE

Al,Ti PAE, H

₂

SO

4

Si

₃

N

₄

, SiO

₂

(PECVD)

Etchant Etchant

Poly-Si TMAH, KOH, EDP Si

₃

N

₄

, SiO

₂

(LPCVD)

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梳狀微致動器梳狀微致動器

旋轉式微馬達旋轉式微馬達

矽面型微加工之基本限制矽面型微加工之基本限制

z

吸附現象

z

薄膜應力

z

表面形態學 (topography)

z 3-D 結構的限制

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吸附吸附 (stiction ( stiction) )現象現象

(b) 錨

基板基板

犧牲層結構層

(a)

蝕刻犧牲層

吸附

吸附示意圖

預防吸附的方法預防吸附的方法

(b) 錨

基板基板

犧牲層結構層

(a)

蝕刻犧牲層

突出物

製作突出物減少吸附的發生

預防吸附的方法預防吸附的方法 (續 ( 續) )

使整個微機械結構具斥水性 (hydrophobic) ，以及避免液體殘留在微機械結構與基板之間著 手，方法更是五花八門，例如以低表面張力的液體清洗之；將浸入甲醇 (methanol) 水溶液 的微結構結凍，爾後甲醇水溶液直接昇華；以 p-dichlorbenzene 清洗之，在真空中可以很 輕易的昇華；還有 t-butyl Alcohol 、液態二氧化碳 (CO₂

) 等化學藥品，都可以用來減少吸

附的發生。

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-31- 薄膜

基板 (a)

(b)

基板

薄膜

薄膜與基板間因殘留應力而產生彎曲

(a) 薄膜受到壓應力 (b) 薄膜受到拉應力

薄膜應力現象薄膜應力現象

(b) 錨

基板基板

(a)

向上彎曲應力抵消

薄膜A 薄膜B

沈積造成反向彎曲的薄膜抵消應力

薄膜應力的控制薄膜應力的控制

表面形態學牽涉到幾個方面，當設計兩層 2 μm 的多晶矽微機械結構時，整個表面輪 廓相差最大的高度將到達 4 μm 以上，如此不僅造成光阻塗佈與曝光的困難，影響到 解析度與深寬比，而且後續沈積之薄膜時也會有階梯覆蓋的問題，所以設計愈多層的結構，將使製程變得窒礙難行，當然平坦化可以多少解決問題，例如旋塗式玻璃

(SOG)、磷矽玻璃(PSG)的回流與化學機械拋光 (CMP)等平坦化製成，但仍必須考慮

衍生之製程上的問題。

表面形態學表面形態學

注意表面輪廓差異

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Hinged structures

Schematic of the fabrication process for surface-micromachinined microhinges.

Ming C. Wu, UCLA

3- 3 -D D 結構的限制與突破結構的限制與突破

R. S. Muller, Berkeley

(請自行從網站下載資料)

http://www.memsrus.com/documents/PolyMUM Ps.DR.v11.pdf

國外

國外MEMS

MEMS代工服務

代工服務…

… MUMPs

MUMPs ( multi ( multi- -user MEMS process ) Process user MEMS process ) Process

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Micromotor

Micromotor fabricated by fabricated by MUMPs MUMPs Process Process

矽體型微加工與應用技術

z

矽材料的機械性質

z

矽體型微加工技術

溼式蝕刻

乾式蝕刻

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Flow sensor

Accelerometer

V-groove Neural microprobe

Force sensor

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-39-

Mechanical properties of some basic thin film materials Mechanical properties of some basic thin film materials

These mechanical properties may depend on the deposition processes.

Three Working Planes of Silicon Substrates Three Working Planes of Silicon Substrates

Ref: Prof. Hsu, Tai-Ran, ITRI Lecture, Jan., 2001

(100) Plane (110) Plane (111) Plane

0.543 nm 0.768 nm 0.768 nm

0 .7 6 8 n m

Normal plane: Diagonal plane: Incline plane:

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矽濕式蝕刻技術矽濕式蝕刻技術

Silicon Wet Etching Technique Silicon Wet Etching Technique

Effects of mask geometry and agitation for isotropic wet etching

Isotropic Etching of Silicon Isotropic Etching of Silicon

z

Etchant:

HNA (HF, HNO

₃

, CH

₃

COOH)

z

Room temperature (<50℃)

z

Diffusion control

z

High etching rate (50μm/min)

z

Undercut mask

z

Mask:

Au/Cr or Si

₃

N

₄

is good SiO

₂

is simple

z

Undercut嚴重

z

Dimension定義嚴重失真

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-43-

Anisotropic Etching of Silicon Anisotropic Etching of Silicon

z Etchant:

KOH, TMAH, EDP, H₂N₄

(110) (100)

蝕刻液組成溫度

(°C) 蝕刻率

(μm/min) (100)/(111) 蝕刻率比值

摻雜硼蝕刻率降低倍數

蝕刻幕罩與 蝕刻率(nm/min)

KOH (water) KOH (isopropyl)

44 g 100 ml

50 g 100 ml

85

50

1.4

1.0

400:1

≥10²⁰cm^-3 降低20倍

二氧化矽(1.4) 氮化矽

ethylenediamine pyrocatechol (water) ethylenediamine pyrocatechol (water)

750 ml 120 g 100 ml 750 ml 120 g 240 ml

115

0.75

1.25

35:1

≥7×10¹⁹cm^-3 降低50倍

二氧化矽(0.2) 氮化矽,金,鉻, 銀,,銅,鉭

TMAH (water)

25 % 80 0.4 * ≥2.5×10²⁰cm^-3

降低40倍

二氧化矽

H₂N₄

(water, isopropyl)

100 ml 100 ml

100 2.0 * 無相關性 二氧化矽,鋁

NaOH (water)

10 g 100 ml

65 0.25-1.0 * ≥3×10²⁰cm^-3

降低10倍

二氧化矽(0.7) 氮化矽

蝕刻液組成與蝕刻特性蝕刻液組成與蝕刻特性

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Etching apparatus Etching apparatus

temperature controller water out

water in

pump water

hot plate

thermal couple

wafer etchant water nitrogen in

Corner Compensation Corner Compensation

EDP etchant KOH etchant

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Mesa microstructures etched in TMAH-BR solution and pure solution without using the corner compensation technique.

Pure TMAH

BR-Added

(添加劑)

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蝕刻終止技術蝕刻終止技術

Etching stop technology Etching stop technology

矽晶片薄膜

二氧化矽

薄膜氫氧化鉀

(a) 薄膜蝕刻終止 (b)

摻雜濃度蝕刻終止

必須使用雙面拋光晶片

矽晶片 p+ 單晶矽

二氧化矽

p+ 微結構氫氧化鉀

(a) (b)

蝕刻率與摻雜物質的型態及摻雜濃度有關

隔膜懸臂樑

金字塔結構皺狀結構

微探針結構碗狀結構

經由摻雜濃度的改變與摻雜區域的控制、蝕刻液的選擇以及選擇適當的蝕刻終 止技術，逐漸發展出摻雜選擇性蝕刻 (doping selective etching) ，可以製作出隔 膜、懸臂樑、金字塔型、皺狀 (corrugated) 、探針、碗狀等特定微機械結構。

利用選擇性蝕刻、蝕刻終止技術所得之各種不同形狀之微結構

(26)

-51- Si₃N₄

Si

(b) 微影及用RIE蝕刻Si₃N₄

(c) 在KOH蝕刻液中蝕刻

Si PR Si₃N₄

Si Si₃N₄ (a) LPCVD沉積Si₃N₄

矽體型微加工之基本限制矽體型微加工之基本限制

z 3-D 結構的限制

z

蝕刻保護的必要性

z

應力問題

製程的殘留應力

(高溫製程、薄膜沉積、薄膜改質)

膜薄間因熱膨脹係數不同所造成的殘留應力

(27)

受限於單晶矽的鑽石立方結晶，蝕刻出來的角度是特定而無法改變的，不能蝕刻出特殊形狀的微結構，所以設計元件時就得考慮結構上的基本限制。

3- 3 -D D 結構的限制結構的限制

蝕刻保護的必要性蝕刻保護的必要性

矽晶片

元件保護層

矽晶片元件經由側壁被蝕刻

氫氧化鉀蝕刻

二氧化矽

氫氧化鉀從側壁滲入破壞元件

正面元件

矽晶片螺絲懸緊

O-ring 二氧化矽

壓克力或鐵氟龍夾具

利用鐵氟龍或壓克力夾具保護正面的元件

鐵氟龍夾具

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-55-

薄膜應力的控制薄膜應力的控制

Heavily Boron Doped Silicon Layer Microstructures

未經處理之P⁺

layer (高應力形變)

經退火處理之P⁺

layer (低應力形變)

中區微機電中心技術資料

矽乾式蝕刻技術矽乾式蝕刻技術

Silicon Dry Etching Technique

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感應耦合電漿蝕刻(ICP-RIE)系統,

PIDC

反應性離子蝕刻(RIE)系統,

NTNU MOEMS Lab.

High

High- -aspect aspect- -ratio, Anisotropic Silicon Etching ratio, Anisotropic Silicon Etching Techniques Techniques by Inductively by Inductively Coupled Plasma Reactive Ion Etching (ICP

Coupled Plasma Reactive Ion Etching (ICP- -RIE) RIE)

Mask材料選擇的原則：高選擇比, 蝕刻深度, 非等向性…

感應耦合電漿之高深寬比非等向性矽蝕刻技術感應耦合電漿之高深寬比非等向性矽蝕刻技術

mask PR, metal, Si

₃

N

₄

, SiO

₂

, Si, Polysilicon…...

substrate PR, metal, SiO

₂

, Si, Polysilicon…...

Plasma

etch stop

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-59-

STS’s ASE (Advanced Silicon Etch) Process

(Bosch Patent)

交替蝕刻與高分子鈍化過程

(C

₄

F

₈

/SF

₆

)：

1. 矽壁沈積鈍化高分子

C

₄

F

₈被電漿分解成活性機，並進行高分子沈積反應，使壁上形成鈍化膜

2. 矽底部的高分子與矽被蝕刻

SF

₆被電漿分解成F^-，先蝕刻鈍化膜再蝕刻Si

3. 交替反覆，平衡鈍化沈積與蝕刻步驟

選擇適當的反應氣體，以維持蝕刻與鈍化的平衡沈積膜必須具有良好的一致性，並足以保護側壁 silicon

mask

Sidewall polymeric passivation (nCF₂)

( a )

nCF_x⁺ nCF_x^-

nCF_x^- nCF_x⁺

silicon

mask Sidewall polymeric passivation (nCF₂)

( b )

CF_x

F^- SiF_x SF_x⁺

SF_x⁺

Source: 鍾震桂等人, 第三屆奈米工程暨微系統技術研討會, 新竹, (1999)

Alternating etch and polymerization process

MCNC, USA

Comb-driver Nested Gears

Micromotor Gyroscope

(31)

Dry Release Process Dry Release Process

(a)

Si

Si SiO₂

(b)

PR

(c)

DRIE trenches

(d)

HF etching

(e)

metallisation

(f)

assembly

SOI (Silicon on insulator) SOI (Silicon on insulator) Fabrication Process Fabrication Process

(32)

-63- Cornel Marxer and Nicolaas F. de Rooij J. of Lightwave Technology, 17(1), 2-6, 1999

DRIE Bulk Micromachining for Optical Switch DRIE Bulk Micromachining for Optical Switch

(SOI Fabrication Process)

非矽基微加工技術非矽基微加工技術

z

LIGA與LIGA-Like製程與應用技術

z

SIGA製程與應用技術

z

軟式微影製程與應用技術

(33)

2. 顯影

4. 金屬模仁

6. 脫模

Mould cavity Resist structure

Plastic structure

5.模造 3. 電鑄 1. 光刻

Plastic (moulding compound)

Metal Resist structure

Electrical conductive base plate Base plate Absorber structure Maskmembrane

Resist

Source: Institut für Mikrotechnik Mainz (IMM), Germany

Li thographie:

光刻

G alvanoformung:

^電鑄

A bformung:

模造

LIGA製程： LIGA 製程：

MCNC, USA

IMM, Germany

LIGA

LIGA 製程製程 vs. 類 vs. 類LIGA LIGA 製程製程

光刻源的差異

LIGA 製程：

同步輻射X光

類LIGA 製程：低成本替代性光源

z

加工深度數mm、次微米級精度、深寬比＞100

z

同步輻射光源為一龐大且昂貴的設備

z

X-ray 光罩製作複雜且成本高

z

加工深度≦ 1mm、微米級精度、深寬比≦50

z

紫外光–厚膜光阻微影製程

z

準分子雷射

z

反應性離子蝕刻

(34)

-67-

Synchrotron Radiation Research Center (for LIGA process) Synchrotron Radiation Research Center (for LIGA process)

JAPAN SPring-8

USA APS FRANCE ESRF

ICP-RIE System Excimer Laser System UV mask aligner

Low- Low -cost Exposure System (for LIGA cost Exposure System (for LIGA- -like process) like process)

Instrument Technology Research Center, ITRC

Comparison of a low energy x-ray mask (left) and a high energy x-ray mask (right) both designed and created at Wisconsin.

4μm Gold on a 1μm SiN membrane

50μm Gold on a 400μm Si substrate

Photomask

Photomask of X- of X -ray Lithography ray Lithography

(35)

Source: http://daytona.ca.sandia.gov/LIGA/mask.html ( Sandia National Laboratory, USA )

Photomask

Photomask of UV Lithography of UV Lithography

(a) CAD Layout (b) Chrome Mask

台灣師範大學機電科技學系 C. R. Yang, NTNU IMT具厚膜光阻及電鑄起始層的試片製備方法具厚膜光阻及電鑄起始層的試片製備方法

Substrate with seed layer Special Special Photoresist Photoresist

Spin coater

Vacuum

Spin coating process

Dry film Dry film

Substrate with seed layer

Laminating process

Glass plate Substrate with seed layer

Pressing machine

Solvent bonding process Solvent layer Solvent layer Polymer film Polymer film

Spacer

Polymerized resist Polymerized resist

Casting machine

Casting process Glass plate Substrate with seed layer

Pretreatment glass plate Separation foil

Polymer film

Separation foil

(36)

-71- (1) 塗佈光阻

聚合物基材

(2) 光蝕刻

雷射光

電鑄起始層

(3) 金屬濺鍍

金屬

(4) 電鑄

金屬模

聚合物 (5) 研磨修整

(6) 剝離

(7) 熱壓印成形

(8) 脫模

substrate seed layer

photoresist nickel

光學元件之LIGA製程示意圖

母模幾何形狀與電鑄起始層位置對電鑄沈積層的影響示意圖

Schematic of a X-ray mask/substrate scanner

Source: http://daytona.ca.sandia.gov/LIGA/mask3.html

X-Ray Scanner DEX 02

JENOPTIK Mikrotechnik GmbH

X- X -ray Deep Lithography Scanner ray Deep Lithography Scanner

(37)

Key Features of X

Key Features of X- -ray LIGA Microstructures ray LIGA Microstructures

z

Realization of arbitrary shape

z

Extreme structure height (>mm)

z

Extreme aspect ratio (>100)

z

Minimum lateral dimensions 0.5±0.1μm

z

Surface roughness 0.03-0.05 μm

z

Vertical & smooth sidewalls

z

Wide variety of materials

z

Successful in mass fabrication

準分子雷射微加工技術準分子雷射微加工技術

以不同雷射，加工 Polyimide 的結果比較：

(a) Nd-YAG laser, (b) CO

2

laser, (c) Excimer laser

F

₂

(157 nm)、ArF (193 nm)、KrF (248 nm)、

XeCl (308 nm)、XeF (351nm)

(38)

-75-

Excimer

Excimer Laser Micromachining Laser Micromachining

Laser LIGA technology Laser LIGA technology

Fresnel structure ablated into dry film with 50 μm thick

Nickel electroplated metallic microstructure

以控制工件平台運動狀態之方式進行雷射加工

(39)

Excimer

Excimer Laser Laser Micromachining: Mask Dragging Micromachining: Mask Dragging

以光罩拖拉（移動工件平台）技巧進行雷射加工的方式

shaped mask

可快速製作不同幾何斷面之微流道

準分子雷射單光罩多層階加工技術準分子雷射單光罩多層階加工技術

光罩圖案

雷射聚焦成像

加工圖案重疊

（光罩移動）

（工件固定）

光罩圖案

1 2 3

2 1

2 3

3 3

3 八階光罩組合

準分子雷射微透鏡加工技術

(40)

-79-

準分子雷射微加工準分子雷射微加工

微光學繞射元件製作與檢測

微光學元件檢測系統

像素5 μm四階全像片 “HELLO” 影像輸出

焦平面光強度十六階微透鏡陣列

孔徑250 μm、焦距15 mm

表面檢測光學檢測 準分子雷射LIGA製程

Applications of Ultrathick Photoresist for Microstructure Fabrication

光罩對準UV曝光系統 特殊光阻塗佈機

●

Low-Cost LIGA製程的發展因素：

(Poor-Man LIGA Technology)

z

厚膜光阻材料的開發

z

特殊光阻塗佈機的發展

z

UV曝光設備的改良

● 厚膜光阻材料

AZ4000 series,

Hoechst (Germany)

ma-P 100, ma-N 400,

Micro resist technology (Germany)

PMER P-LA 900,

tok (Japan)

Probimide,

Olin microelectronic materials (Japan)

THB-611P, THB-430N,

JSR (Japan)

SU-8,

Microlithography chemical corporation (USA)

(41)

SU- SU -8 8 厚膜光阻厚膜光阻 UV UV -LIGA - LIGA製程製程

光阻微結構 vs. 螞蟻

國科會精密儀器發展中心 (PIDC)

電鑄鎳金屬結構

Preparing

Preparing Photoresist Photoresist Reflow Lens Pattern Reflow Lens Pattern

H. Toshiyoshi

(42)

-83-

Transferring

Transferring Photoresist Photoresist Pattern into Silicon Pattern into Silicon

G. Engelmann, J. Micromech.

Mmicroeng., (1994) 152-154

(b) 曝光顯影

(c) 鍍Cr/Au

(d) Lift-off

(e) 正光阻 (犧牲層)

(f) 曝光顯影

(g) 鍍Ti/Cu

(i) 曝光顯影

(j) 電鑄Ni (h) 負光阻

(k) 去除光阻結構釋放 (a) 上正光阻

犧牲層厚膜光阻製程技術

(43)

Movable Microstructure fabricated by Single Mask Movable Microstructure fabricated by Single Mask

Lithography & Dry Releasing Techniques Lithography & Dry Releasing Techniques

Micro-relay fabrication process

(a) SU-8 resist lithography

(b) Dry etching

(c) Metal Sputtered

Micro-relay, PIDC

SiO₂ Si

Si (a) 熱氧化沉積SiO₂

(b) 微影及用BOE蝕刻SiO₂

(c) 以最佳蝕刻參數蝕刻

Si SiOPR₂

SiO₂

Si

(d) 使用BOE去除SiO₂

Si Cr/Cu

(e) 蒸鍍電鑄起始層Cr/Cu

Si Cr/Cu

Ni

(f) 微鎳電鑄

(g) 脫模

In German: In English:

Silizum-mikrostrukyur Silicon-microstructuring Galvanoformum Electroforming

Abformung Molding

SIGA SI GA製程製程：：

(44)

-87-

Lenses

Gratings Waveguides Holograms

成形方法：

1. Lithography +RIE etching 2. Photoresist reflow

3. Direct writing of e-beam or laser 4. Shaped light beam method 5. Grey tone mask technique

Grey tone mask technique Shaped light beam method

Direct writing of e-beam

SIGA製程應用技術 SIGA 製程應用技術

Lens profile in resist on glass or silicon

Ion etching

Lens profile etched into glass or silicon

Ni stamper

glass UV-curable polymer

UV exposure

Ni stamper

Substrate

Polymer film

(45)

Application of SIGA Process Application of SIGA Process

Fabrication of Silicon Fuel

Fabrication of Silicon Fuel Atomiser Atomiser

Si mold

Ni atomizer

1. Grow oxide and pattern

2. Spin on thick resist and pattern

3. First 275 μm deep DRIE etch

4. Remove oxide and second DRIE etch for an additional 125 μm

6. Polish excess and release 5. Deposit 400 μm of Ni

N. Rajan et al., J. Microelectromechanical Systems, 8(3), 251(1999)

Fabrication of Silicon Fuel

Fabrication of Silicon Fuel Atomiser Atomiser

軟式微影製程與應用技術軟式微影製程與應用技術

軟式微影製程主要是利用一種透明的彈性高分子聚合材料二甲基矽氧 烷(polydimethylsiloxane, PDMS)，作為翻模用的彈性印章(stamp)，利 用印章圖形轉移的方式，並搭配不同的後處理(如蝕刻、灌模等)，來 完成各種不同的微結構。

SU-8 master structure PDMS replica of SU-8 master structure

Hong et al., Columbia University

(46)

-91- n=~60

n=~10

Advantage and Disadvantage of PDMS Advantage and Disadvantage of PDMS

z z Advantage : Advantage :

(1) Favorable mechanical properties (1) Favorable mechanical properties

(such as extreme

(such as extreme flexibility and stability flexibility and stability) ) (2) Good optical properties (2)

Good optical properties

(transparent) (transparent) (3) High biocompatibility

(3) High biocompatibility (4) Peel off the PDMS easily (4) Peel off the PDMS easily (5) Low costs

(5) Low costs

z z Disadvantage : Disadvantage :

(1) Use soft lithography techniques to fabricate (1) Use soft lithography techniques to fabricate (2) The PDMS is poisoned easily.

(2) The PDMS is poisoned easily.

(47)

Variable

Variable- -focusing focusing microlens microlens with with microfluidic microfluidic chip chip

J. Chen et al., J. Micromech. Microeng. 14 (2004) 675–680

Microfluidic

Microfluidic Chip Fabrication Chip Fabrication

J. Chen et al., J. Micromech. Microeng. 14 (2004) 675–680

(48)

-95-

Polymer

Polymer- -based variable focal based variable focal length

length microlens microlens system system

M. Agarwal et al., J. Micromech. Microeng. 14 (2004) 1665–1673

Series of images taken at different volumes of fluid by actuating the variable focal length lens as: (a) DCX lens, (b) DCV lens

M. Agarwal et al., J.

Micromech. Microeng. 14 (2004)

1665–1673

(49)

MEMS- MEMS -based based的奈米科技研究

的奈米科技研究

微反應晶片應用於硒化鎘奈米微粒合成之研製微反應晶片應用於硒化鎘奈米微粒合成之研製

Development of a MEMS

Development of a MEMS--based based microreactormicroreactorfabricated

fabricated for synthesizing composite

for synthesizing composite CdSeCdSenanoparticles

nanoparticles

Introduction of

Introduction of CdSe CdSe nanoparticles nanoparticles

2

E 1 Δ ∝ a

a: particle size UE: band gap

Ref: http://www.qdots.com

(50)

-99-

Quantum-dot LEDs

Ref: Seth Coe et al., Nature 420, 800, 2002.

Identification codes

Ref︰ Shoude Chang et al., Optics Express, 2004.

Biological detection

Ref: Quantum dot, Nature Biotechnology, 21, 2003.

Conventional

Conventional macroscale macroscale reactor reactor

z

Can’t control reaction temperature and reaction time exactly

z

Can’t control of reagent concentrations

size selection process Aging

Injection of Reagents at high

temperature

Hot surfactant

solution Surfactant

Ref: Rogach et al., J. Phys. Chem. B , 103, 1999, 3065-3069.

(51)

Preparation of

Preparation of CdSe CdSe nanoparticles nanoparticles in a in a glass capillary

glass capillary

Ref: Hongzhi Wang et al., Chem. Commun., 2004.

Ref: Hideaki aeda et al., Chem. Commun., 23, 2002.

Preparation of

Preparation of CdSe CdSe nanoparticles nanoparticles in a chip in a chip

Cd(NO3)2·4H2O

Na2S

Ref: Andrew demello et al., Chem.

Commun., 2002, 1136–1137.

What are the benefits of synthesis in microreactor system ?

- rapidly rising temperature

- reaction temperature and reaction time control exactly

- precise control of reagent concentrations - higher plant security

- offering continuous process

Ref: John, Andrew deMello, Lab on a chip, 4, 2004, 11N-15N.

T. Schwalbe et al., Chemical Synthesis in Microreactors, CHIMIA 56 , 2002, 636-646.

(52)

-103-

1. CdSe synthesis section:

- heated at 300℃ to form CdSe nanoparticles

2. Mixing section:

- mixing CdSe nanoparticles with ZnS raw materials

3. ZnS coating section:

- heated at 220℃ to coating ZnS shell

Glass

Glass- -based based microreactor microreactor system for synthesizing system for synthesizing CdSe CdSe nanoparticles nanoparticles

Passive mixing by chaotic advection Passive mixing by chaotic advection

Ref: Liu R. H. et al., JMEMS, 2000.

(53)

Photomask

Photomask of Mi of Microchannel crochannel

(d) etching by HF

(f) fusion bonding

(g) photoresist patteren

(i) lift-off glass

Cr/Au Ti/Pt AZ 4620

(e) remove Cr/Au (b) deposition Cr/Au

(c) lift-off

(a) defined PR patterns

(h) sputter Ti/Pt

Fabrication Process Fabrication Process

This device including - micromixer - microheater - thermal sensor

Corni ng 1737

Pyrex 7740 Soda-lime

Glass etched result Glass etched result

fusion bonding

(54)

-107-

Mixing experiment Mixing experiment

PH indicator:

●

0.31mol/L phenolphthalein/ethyl alcohol solution;

●

1 ml ammonia /16 ml water

●

Flow rate (water): 100~370 μl/min

Ref: Liu, Stremler et al., Journal of Microelectromechanical Systems, Vol. 9, No.2, June 2000;

Dong Sung Kim et al., J. Micromech. Microeng. 14(2004), 1294-1301.

row 2 row 3 row 1

Distribution of temperature at

Distribution of temperature at microreactor microreactor

• IR image of microreactor

• 296.9 ℃ at CdSe nucleation region

• 224 ℃ at ZnS coating region

(55)

Synthesis of CdSe

Synthesis of CdSe nanoparticles nanoparticles

CdSe products blocked up the channel

• Se stock solution:

10 mmole Se+25 g TOP

• Cd stock solution:

266.6 mg Cd(AcO)2 + 20 g ODE，565 mg Oleic acid + 10g TOPO

• CdSe raw solution: 1Cd : 1Se

• Flow rate: 150 μl/min

300 400 500 600 700

Wavelength (nm) 0

0.2 0.4 0.6 0.8

Absorbance (a.u.)

UV UV - - VIS absorption spectrum VIS absorption spectrum

220 ℃ 240 ℃ 260 ℃

• CdSe nucleation region heated on 220, 240, 260 ℃

• Flow rate: 150 μl/min

260℃

220℃ 240℃

(56)

-111-

MEMS fabrication process and its application to nanotechnology

微機電製程技術與其在奈米科技之應用 微機電製程技術與其在奈米科技之應用