Course description : MEMS

(1)

Introduction to MEMS

(Lecture 1)

Prof. Dong-Weon Lee

MEMS & Nanotechnology Laboratory School of Mechanical Systems Engineering

Chonnam National University

http://love.chonnam.ac.kr/~mems MEMS@chonnam.ac.kr

(2)

Textbook:

- Lecture notes (very important source) - Foundations of MEMS, Chang Liu.

Reference book:

- Foundations of Microfabrication: The Science of Miniaturization, by Marc Madou

- Microsystems Design by Stephen Senturia

- Micromachined Transducers Sourcebook by Greg Kovacs.

Website (contains frequent updates, homework assignment, links) - http://mems.chonnam.ac.kr

Dong-Weon Lee Contact - E-mail : mems@jnu.ac.kr, 1A-209-2

Resources

(3)

Course description : MEMS

MEMS : MicroElectroMechanical Systems

• 공학의 새로운 지평을 열어준 복합적이면서 필수적인 학문

• 초소형 정밀기계기술은 각종 센서와 액추에이터를 설계하고 제작하는

것을 가능하게 하고 현대의 전자, 기계제품에는 없어서는 안 될 중요한 부품을 만드는 것을 가능하게 함

• 초소형 정밀기계 기술은 근대의 반도체 제작 기술의 발전과 더불어 성 장을 함

• 현재는 나노기술의 증장과 정밀 의료기기와 고기능 정보기기의 필요성 이 대두됨에 따라 MEMS 분야의 가공기술은 더욱 더 중요한 기술로 부 각됨

• 전통적인 공학의 두 분야인 기계공학과 전기공학의 지식은 물론 여러 분야의 기술과 기초지식이 필요함

(4)

Micro/NanoElectro Mechanical Systems (MEMS/NEMS) technology is a core technique that can make revolutionary changes in many application fields such as Mechanics, Electronics, Optics, Communication systems, Biotechnology and etc. MEMS is a research area dealing with the design, fabrication and application of micro-sensors and micro-actuators used for micro optical, bio, communication and automobile systems. MEMS has a great deal of influences on many application fields, and various

knowledge and technologies are required in its design and fabrication.

This course provides undergraduate students with fundamentals about the design and fabrication of MEMS systems and introductions of their application areas.

This course will first introduce the fundamental concepts of

Micro/NanoElectroMechanical Systems and provide information about micro/nanofabrication processing technologies, which are the essential manufacturing methods in the realization of MEMS/NEMS systems. Also, typical application examples of MEMS devices in the areas such as

inertial, optical, RF, and bio MEMS will be introduced.

Course description : MEMS

(5)

Students’ objectives

• 센서와 액추에이터를 포함하는 미세기계전자 트랜스듀서를 설계하는 학 문분야의 경계를 넘는 중요한 기초지식 획득 : 수강생은 간단한 기계전자 소자의 설계임무와 제작 및 특성평가와 관련한 능력을 학습함

• MEMS에 관하여 전혀 알지 못하였던 학생들이 미세가공과정에 관한 기 초와 중요성을 이해하고 미래의 응용에 관한 새로운 가공을 종합해 만들 수 있는 기초지식을 확고히 학습

• 전통적이고 동시에 수반되는 사례 학습을 통해 MEMS의 일반적인 연습 설계와 가공 과정을 학습함 : 유한요소법을 통한 구조 설계 및 마스크 레 이아웃 툴을 활용한 마스크 설계

• 미세기계전자소자의 개발에서 고려해야 할 항목(설계, 강건, 성능, 가공, 비용 등)을 평가하기 위해 분석적이고 실제적인 요령을 학습

(6)

Students’ objectives

1. Introduction to MEMS and fabrication

Broad-stroke overview – history, trends, transducers First-pass discussion of fabrication

2. Introduction to principles of sensing and actuation

Analysis oriented.

Electrostatic, piezoresistivity, piezoelectricity, thermal sensing and actuation Basic electromechanical analysis for beams and membranes

Representative devices, analysis, and brief discussion of their fabrication when necessary

3. In-depth discussion of microfabrication methods

Fabrication oriented.

Bulk and surface micromachining techniques.

Comparison of fabrication processes for targeted structures

4. Case studies

Application oriented.

Design, fabrication, application mixed together.

Get ready for final project.

(7)

What to expect from this class

1. MEMS is a young and developing field

frequently encounter empirical rather than rigorous analysis;

developing text and new materials

2. MEMS is an interdisciplinary field

be willing to expose yourself to jargons and concepts from non-major fields climb the learning curve by reading recommended reference papers, notes and text book

3. Students are from diverse background

ME, EE, Materials Science, Chemistry, Chemical engineering

Contents of teaching must balance all students while minimizing redundancy Learn to benefit from the company of multi-disciplinary students

4. Unique exam schedule and style

One midterm exam tests basic understanding of concepts;

A project-based final exam tests the comprehensive understanding of inter- related materials, design and fabrication issues.

(8)

Text book

강의교재

• MEMS의 기초(Foundations of MEMS) 및 강의자료(홈페이지)

• 다양한 배경을 가진 학생들이 쉽게 접근할 수 있게 중요 어휘 및 자주 이용되는 개념을 중심으로 소개

• MEMS 지식의 토대가 될 수 있는 설 계, 제조, 재료 간의 균형을 이루고 있음

(9)

Text book : Contents

1. 소개

2. 미세 제작기술

3. 전기적/기계적 필수 개념 4. 정전기적 센싱과 액추에이션 5. 열센싱과 액추에이션

6. 압저항 센서

7. 압전센싱 및 액추에이션 8. 자기센싱 및 액추에이션

9. 센싱과 액추에이션 요약 (9.1절)

10. 벌크 미세 가공기술과 실리콘 비등방성 식각 11. 표면 미세 가공

12. 폴리머 MEMS

13. 마이크로 유체공학의 응용

14. 주사 프로브 현미경을 위한 기기 15. 광학 MEMS

16. MEMS 기술 경영

(10)

Lecture schedule

1주: MEMS introduction

2주~3주: Scaling Law & Basic in Microelectronics (Semiconductor Devices)

4주~5주: Basic Silicon Process: Photolithography, Oxidation, Deposition, Etch, etc 6주~7주: Surface Micromachining and Bulk Micromachining

8주: Mid-term Examination (4월 25일 09:00 ~ 11:00) 9주: Device design (Mask design using a CAD program)

10주: Structure optimization using a FEM  Pressure Sensor 11주: Micromachined Sensors and Their Applications

12주: Micromachined Actuators and Their Applications

13주: Basic Experiments in MEMS  Oxidation, Photolithography and Etch 14주: Term project presentation

15주: Final examination (6월 13일 09:00 ~ 11:00)

(11)

Term project

# 설계 1 : 압력센서 구조 이해 및 최적 설계

FEM을 이용하여 구조물을 해석한 후, 마스크 설계를 위한 CAD 프로그램을 이용하여 압력센서를 설계함

목표: L-edit프로그램 압저항형 압력센서 마스크를 설계함 평가 항목

1. Array를 이용하여 배열 하였는가?

2. 마스크의 positive, negative를 이해하고 있는가?

3. Instance를 사용하여 디자인 하였는가?

4. Align mark를 적절하게 디자인 하였는가?

5. 정확한 치수를 기입 하였는가?

# 설계 2 : Term project

교과목에서 배운 지식을 바탕으로 주어진 과제에 관한 새로운 아이디어 또 는 최적의 구조에 관한 아이디어 발표

(12)

• Grading policies (Tentative)

– Exams : Midterm (30%), Final (30%)

– Homework (15%) : including term projects (MEMS fabrication) – Attendance : 5%

– Quiz (20%)

– Personal reasons for the absence is not accepted.

• Announcements

– Please visit the class website as many as possible and check announcements.

– Homework submitted after the due date are exclusive in grading.

Grading policy

(13)

Overview of MEMS

(14)

Get Scale Straight

1 m = 1/1000 mm

1 nm = 1/1000 m = 1/1,000,000 mm Characteristic length scale of MEMS

1 micrometer to 1 mm

Special case: large distributed array.

15 mm

Large array Small nodes

(15)

10,000 Meter Scale

(16)

1000 meter scale

(17)

100 meter scale

(18)

10 Meter

(19)

1 meter

(20)

0.1 m

(21)

0.01 meter, or 10 mm

(22)

0.001 meter, or 1 mm

(23)

0.1 mm, or 100 micrometer

(24)

10 micrometer

(25)

1 micrometer

(26)

0.1 micrometer

(27)

0.01 micrometer, or 10 nm

• The realm of molecules, DNA, proteins, and atoms.

(28)

Velcro ( 1 mm)

(29)

Artery ( 1 mm)

(30)

Muscle Fiber ( 1 m)

(31)

At 1 micrometer and slightly below …

Bacteria

Cell division

(32)

 Semiconductors

 MicroElectroMechanical Systems

 Micro Systems T echnology

 Micromachining

 Micromachined T ransducers(Sensors & Actuators)

 Nanomachining

 Nanotechnology

Terminology

(33)

Brief history in MEMS

(34)

Brief history in MEMS

(35)

Required knowledge

Dream come true

(36)

Main material for MEMS

(37)

4 inch wafer

Gyroscope

From sand to useful devices

(38)

Emerging technology

 니콜라스 퀴뇨: 증기자동차 in 1769

 칼 벤츠 & 고틀리프 다임러: 가솔린 자동차 in 1886

 아르망 푸조: 푸조사 설립 in 1889

 오펠사: Rak 2 발명 in 1927 (200 km/h)

 다임러-벤츠: 최초의 양산 디젤 260D 발표 in 1936

 포드: 2점식 안전벨트 장착 in 1956

약 4500년 전 1482년

B.C. 3000년 이전

Materials, Electronics and Sensors

(39)

Paradigm shift

기존의 순수 기계공학

새로운 융합기계 필요성 대두

(40)

Paradigm shift

Mechanical Engineering Electrical Engineering

Future and Convergence Engineering

 More miniaturization, functions

 Less expensive

(41)

Microelectronics – The IT Backbone

• Microelectronics and optoelectronics

– Infrastructure of today’s information technology – communication, computation, control

– Model, design, fabrication technology, and device implementation for tomorrow’s micro processors and communications chips

Fiber for fast internet IBM GB hard drive Low lost, photo-

Quality Ink Jet Personal communication

Digital photography

(42)

Micro Electro Mechanical Systems

Accelerometer (Analog Devices)

Digital Light Processors (DLP) (Texas Instruments)

Ink Jet Nozzle (HP)

Miniaturization

& Resolution (1 m-1mm)

Mechanics/

Electronics Integration

Parallel Fabrication

Paradigm shift

(43)