MEMS TECHNOLOGIES AND

ANALYSIS OF MERITS AND

DEMERITS THEREOF

- BIPRASISH RAY

(2015H123031G)

CONTENTS

INTRODUCTION

FABRICATION PROCESS

FABRICATION TECHNIQUE

APPLICATIONS

ADVANTAGES AND DISADVANTAGES

CONCLUSION

FUTURE SCOPE

WHAT IS MEMS?

MEMS stands for MICROELECTROMECHANICAL SYSTEMS

MMicro: Small size, micro fabricated structures.

E Electro: Electrical signal control.

MMechanical: Mechanical functionality.

S Systems: Structures, Devices, System Controls.

MEMS devices generally range in size from 20

micrometers to a millimeter

COMPONENTS OF MEMS DEVICE MICROACTUATORS AND

MICROSENSORS FORM THE

MOST IMPORTANT

COMPONENTS OF A MEMS

DEVICE.

N

S

EW 2 Axis Magnetic

Sensor2 Axis

AccelerometerLight Intensity

SensorHumidity Sensor

Pressure Sensor

Temperature

Sensor

FABRICATION OF MEMS

Deposition Patterning Etching

Physical Chemical Lithography Dry Wet

Photolithography

PACKAGING:

o Metal can package

o Plastic package

o Ceramic package

FABRICATION TECHNIQUE

The fabrication technique of MEMS devices is called

Micromachining or Microfabrication.

The fabrication of MEMS evolved from the process

technology in semiconductor device fabrication.

Two basic methods of MEMS integration are:

Surface Micromachining

Bulk Micromachining

SURFACE MICROMACHINING

In surface micromachining, the MEMS sensors are formed on

top of the wafer using deposited thin film materials. The

surface micromachined sensors use the capacitive

transduction method to convert the input mechanical signal

to the equivalent electrical signal.

One of the most important processing steps that is required of

dynamic MEMS devices is the selective removal of an

underlying film, referred to as a sacrificial layer, without

attacking an overlaying film, referred to as the structural

layer, used to create the mechanical parts.

Enables low cost accelerometers.

BULK MICROMACHINING

Bulk micromachining is an extension of IC technology for the

fabrication of 3D structures.

The whole thickness of a silicon wafer is used for building the

micro-mechanical structures.

The transduction mechanism that has been widely used is

the piezoresistive effect. In piezoresistive materials, a change

in the stress causes a strain and a corresponding change in the

resistance.

Enables high performance microactuators and microsensors.

APPLICATIONS OF MEMS

APPLICATIONS OF MEMS

ADVANTAGES AND DISADVANTAGES

Minimize energy and

materials.

Improved reproducibility.

Improved sensitivity,

accuracy and reliability

Low cost and low power.

Easier to alter the parts of

a device as compared to

its macro counterpart.

Farm establishment

requires huge

investments.

Polysilicon is a brittle

material.

Design includes very

much complex

procedures.

CONCLUSION

This enabling technology promises to create entirely new categories of products.

MEMS will be the indispensible factor in advancing technology.

As with all emerging technologies had been predicted to revolutionize technology and our lives.

FUTURE SCOPE

In order to avoid the need for a multitude of wires, such

sensors must be self sustaining and able to communicate

wirelessly.

As a result, not only more sensors are needed, but also small

energy generating modules and wireless transmission

components. Clearly, the increased numbers of devices will

drive size reduction which in turn will enable higher levels of

integration.

This prediction combined with the foregoing discussion on the

advantages of MEMS over macro devices lead us to predict

that MEMS will soon be integrated into our everyday life just

as the computers have been.