1001207-100BMC-孟晏

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IC製程簡介與生物晶片
3D Biochip
2D Biochip
報告人:蔡孟晏
指導教授:張憲彰 老師 2011120
1
Outline
1. 生物晶片(Biochip)
Evaporation
製程部
分簡介
2. 薄膜
沉積
PVD
Sputtering
CVD
APCVD
LPCVD
PECVD
Wet etching
Dry etching
3.蝕刻
RIE
2
Biochip (生物晶片)
• 傳統上,在實驗室檢測生物樣本大多需要眾
多儀器與專業知識才能進行檢測。
• 近十幾年由於製程技術的進步,將微機電製
程(Micro electric Mechanical System, MEMS)
運用於檢測上因而誕生了生物晶片。
• 生物晶片大多運用電動力學原理於濃縮、分
離、捕捉、集中樣本。
3
晶片製作過程
清洗
載玻片
蒸鍍
以丙酮、異丙醇
清洗玻片上的油
脂、有機物質
蒸鍍上金和鈦
的載玻片
曝光、蝕刻
定義電極圖形
4
Outline
1. 生物晶片(Biochip)
Evaporation
製程部
分簡介
2. 薄膜
沉積
PVD
Sputtering
CVD
APCVD
LPCVD
PECVD
Wet etching
Dry etching
3.蝕刻
RIE
5
Thin films Deposition
Physical Vapor Deposition (PVD) Chemical Vapor Deposition (CVD)
(1) Evaporation Thermal
(2) E-beam evaporation
(3) Sputtering
(1) Atmospheric pressure CVD (APCVD)
(2) Low pressure CVD (LPCVD)
(3) Plasma enhanced CVD (PECVD)
6
http://python.rice.edu/~arb/Courses/chem360_06.htm
Thermal Evaporator
 This can be reached only
under high vacuum conditions:
pressure of <1 mPa
Aluminum
To pump
 Consequently expensive
pumping systems and long
pumping times are needed .
 The distance between
evaporator and the substrates
Power supply has to be comparable with
free path for evaporated
atoms.
7
Electron Beam Evaporator
To pump
Power
supply
electron
beam
• Electrons are emitted from the
resistively heated filament and
accelerated between the filament
and accelerating grid.
• Electrostatic deflection plates
control the e-beam position
• Strong magnets generate magnetic
field causing 270º bending of the ebeam
• E-beam can be restored across the
charge to melt a significant fraction
of the surface.
• Crucible (坩堝) is water-cooled to
reduce the contamination
• Many crucibles for compounds
• Problem for semiconductors:
radiation damage (UV, X-ray) 8
Evaporator
Electron Beam Evaporator
Thermal Evaporator
9
DC sputtering
Sputtering (濺鍍)
Magnetron sputtering
Radio frequency (RF) is a rate of oscillation
in the range of about 30 kHz to 300 GHz
RF sputtering
• The major PVD method in silicon
technology
• Using ion bombardment to introduce
mass transfer
• Low temperature process can deposit
virtually any materials, contain metals,
ceramics, organic.
• Can deposit composite film (alloy)
with controllable composition.
10
• Major disadvantage: substrate damage
Sputtering & Evaporation
Advantages
Disadvantages
Sputtering
1. Uniform thickness over
large substrates.
2. Control film thickness
easily.
3. Control film alloys easily.
4. Batter adhesion.
1. Expensive equipment.
2. Ion bombardment is
critical to some materials.
3. More impurities due to
lower vacuum.
Evaporation
1. Cheap equipment.
2. Lower impurities due to
higher vacuum.
1. Difficult to deposit
alloys.
2. Need higher vacuum.
3. Difficult to melt high
melting point material.
4. Poor adhesion.
PVD
11
晶片製作過程
清洗
本實驗室的生物晶片是使用電子束蒸鍍
以丙酮、異丙醇
(Electron Beam Evaporator)在載玻片上進
清洗玻片上的油
行鈦與金的物理性薄膜沉積。
載玻片
脂、有機物質
薄膜沉積是先鍍上鈦隨後才是金,這是
因為金無法與載玻片有良好的貼附性才使
用鈦當作金與載玻片之間的介質。
曝光、蝕刻
蒸鍍
蒸鍍上金和鈦
的載玻片
定義電極圖形
12
Outline
1. 生物晶片(Biochip)
Evaporation
製程部
分簡介
2. 薄膜
沉積
PVD
Sputtering
CVD
APCVD
LPCVD
PECVD
Wet etching
Dry etching
3.蝕刻
RIE
13
Chemical Vapor Deposition (CVD)
Chemical vapor deposition (CVD) forms a thin film on the surface of a substrate by
thermal decomposition and/or reaction of precursor molecules (gaseous compounds)
Al in TiN
265℃
1. Vaporization and transport of precursor molecules into a reactor.
2. Diffusion of precursor molecules to the surface of the substrate.
3. Adsorption of precursor molecules to the surface and further diffusion across the surface.
4. Decomposition of precursor molecules and incorporation into solid films.
5. Desorption of volatile byproducts into the gas phase.
Silicon : SiH4(g) → Si (s) + 2H2(g)
Silicon dioxide: SiH4(g) + O2 → SiO2(s) + 2H2(g)
Silicon Nitride: 3SiH4 + 4NH3 → Si3N4 + 12 H2
Tungsten: WF6→ W +3F2
Slowest Step Dominates
• Reaction-rate limited process
• Mass-transport limited process
14
Atmospheric CVD (APCVD)
gas
gas
SiO2 deposition
SiH4 (g)+O2 (g) →SiO2 (s)+2H2 (g)
High deposition rate
• Poor uniformity, high contamination level.
• Operation temperature 500~800°C
• Application for dielectrics(SiO2, Si3N4)

15
Low Pressure CVD (LPCVD)
TEOS oxide at 700°C
• Low pressure: from 0.1 to 1 Torr
• Used mainly for polysilicon, silicon dioxide and silicon nitride films.
• Can process 200 wafers per batch.
• Typically performed temperature in 300~900 °C
• Allows chemical deposition of thin film with the best quality
16
Plasma Enhanced CVD (PECVD)
PECVD TEOS
Si(OC2H5) + O2 → SiO2+ byproduct
Tetraethyl Orthosilicate (TEOS)
四乙基正矽酸鹽
• High deposition rate at relatively low temp (20~150°C)
• RF induces plasma field in deposition gas
• Developed for silicon nitride and silicon dioxide
17
CVD application
18
Outline
1. 生物晶片(Biochip)
Evaporation
製程部
分簡介
2. 薄膜
沉積
PVD
Sputtering
CVD
APCVD
LPCVD
PECVD
Wet etching
Dry etching
3.蝕刻
RIE
19
Etching
 Film an area define
by lithographic step
removed or etched
away.
 Etching type:
wet etching and dry
etch.
20
Etching Process
• Anisotropic:
- best for making small gaps and vertical sidewalls
- typically more costly
• Isotropic :
- quick, easy, cheap.
- best to use with large geometries, when sidewall slope does not
matter, undercut/release.
21
- rounding of sharp anisotropic corners
Wet Etching
•What is wet etching?
- material removal reaction occur in the liquid .
• Mixtures of acids, bases, and water
- HF, H3PO4, H2SO4, KOH, TMAH, H2O2, HCl, ..
• Can be used to etch many materials
- Si, SiO2, Si3N4, PR, Al, Au, Cu,…
• Etch Rate:
- wide range
• Etch Selectivity
- typically quite high
- sensitive to contamination
• Etch Geometry
- typically isotropic, some special cases are anisotropic.
22
Wet Etching
Advantages:
 Low cost
 Orientation dependant
 Controllable etch rates
 High selective
Disadvantages:
 Contamination
 Dangerous
 Etch rate varied by
temperature and
concentration
23
晶片製作過程
載玻片
 本實驗室的生物晶片是以濕式蝕刻,經
沉積不同物質與不同沉積厚度,所使用
清洗
蒸鍍
的化學藥劑與浸泡時間都會有所改變。
 我們的晶片是沉積金與鈦,所使用的化
以丙酮、異丙醇
清洗玻片上的油
學藥劑分別為金蝕刻液與鈦蝕刻液。
脂、有機物質
 在金的蝕刻時間上大約浸泡45秒。
蒸鍍上金和鈦
 在鈦的蝕刻時間上大約浸泡5秒,蝕刻
的載玻片
液需加熱至90度。
曝光、蝕刻
定義電極圖形
24
Dry Etching
What is dry etching?
 material removal reaction occur in the gas phase
Type of dry etching
 non-plasma based dry etching
 Plasma based dry etching
Advantages:
 Directional etching without using the crystal orientation of Si
 High resolution
 Ease of automation
Disadvantages:
 Some gases are quite toxic and corrosive
 Re-deposition of non-volatile compounds
 Need of specialized (expensive) equipment
25
Method of Dry Etching
• Physical etching:
(e.g. sputtering etch),
mechanical/physical interaction.
• Chemical etching:
- neutral or/and ionized species
interact with the material’s
surface to form volatile products
• Combinations of Chemical
and Physical Etching
- Anisotropic profile, reasonably
good selectivity, and moderate
bombardment-induced damage
26
RF plasma based dry etching
CF4 + e﹣ → CF3 + F +2e﹣
F + SiO2 → SiF4 + O
F + Si3N4 → SiF4 + N
– low dc bias is generated
– the energy of bombarding ions is not sufficient to sputter the substrate
– chemical species are produced in plasma
– removal of substrate materials occurs due to chemistry
– substrates are placed on the grounded electrode
27
photoresist
photoresist
Reactive ion Etching (RIE)
ion
Atom
Free radicals
Etch byproduct
 Chemically reactive plasma is generated
 Cathode is biased with RF power
 Cathode is smaller than the anode dc bias of few hundred of
volts is induced on the cathode
 Positive ions are accelerated across the plasma sheath
 Removal of material is by both sputtering and chemistry
28
Summary
 生物晶片在檢測技術上有著跨時代的進步,於實驗室眾多儀
器的分析處理改進至一片微小的生物晶片上。有體積微小的
優點,還有所需檢測樣本少、檢測時間短、成本低廉。
 薄膜沉積技術在著重材料研發改質的時代裡地位就更顯重要,
未來的世界裡,人類的生活中舉如工業、生醫領域,將因薄
膜技術的應用而獲得更多的進步,同時在講究環保的今日,
PVD的薄膜沉積技術應會被列為技術研發的首要考量。
 蝕刻技術中,乾式蝕刻因具有高度非等向性蝕刻能力,應用
於IC或MEMS的系統製程上有著不可取代的地位,尤其高深
寬比的製程技術,將在奈米結構的發展上產生極大的應用。
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