ABOUT SILICON TECHNOLOGY

1. BY:
HEMANTH THOTA
3RD BTECH-ECE
LBR COLLEGE OF ENGINEERING
MYLAVARAM,VIJAYAWADA

2.  Micro-Electro-Mechanical Systems
 It is the integration of elements, sensors, actuators, and electronics
on a common silicon substrate through micro-fabrication
technology, a manufacturing technology for making microscopic
devices.
 Silicon is the material used to create most integrated circuits used
in consumer electronics in the modern industry. The economies of
scale, ready availability of cheap high-quality materials and ability
to incorporate electronic functionality make silicon attractive for a
wide variety of MEMS applications.
 Other Materials used in MEMS
 Gallium Arsenide
 Titanium Nickel
 Piezoelectric Materials

3. Deposition (Material addition)
spin coating, evaporation,
electroplating, reactive growth, CVD,
sputtering
Lithography
various wavelengths, mask making,
alignment, exposure
Etching (Material removal)
wet chemical etching, dry plasma
etching, gas phase etching,
Wafer bonding
Silicon on insulator wafers (SOI)
Packaging
adhesion, wire bonding

4. There are mainly two fabrication technologies for
mems:
 The first established process is silicon bulk
micromachining using alkaline solutions, which
have a much smaller etch rate of the
crystallographic plane in Si compared with other
planes.
 Poly silicon surface micromachining exploits
differences between deposited poly silicon and
silica layers to form three-dimensional features

5.  Silicon is the most abundant
electropositive element in
The Earth’s crust. So it is
cheap for fabrication process.
 it has high melting point at
1410°c.
 It has high boiling point at
3265°c.

6. :

9. Micro-Opto-Electro-Mechanical
Systems (MOEMS) is not a special class of
Micro-Electro-Mechanical Systems
(MEMS) but in fact it is MEMS merged
with Micro-optics which involves sensing
or manipulating optical signals on a very
small size scale using integrated
mechanical, optical, and electrical systems.
MOEMS includes a wide variety of devices
including Optical switch optical cross-
connect,
tunable VCSEL, microbolometers amongst
others. These devices are usually
fabricated using micro-optics and standard
micromachining technologies using
materials like silicon, silicon dioxide,
silicon nitride and gallium arsenide.

11. The MEMS devices are:
 Switches
 Micro mirrors
 Tunable devices (delay, dispersion, wavelength, bandwidth, dynamic
gain equalization, etc)
Optical MEMS offers:
 Low optical insertion loss
 Low crosstalk
 Transparency (wavelength, polarization, bit rate, data format)
 Low power consumption
The effect of moving optical elements is stronger than electro optic,
thermal-optic effects.
Very efficient beam steering devices.

12.  Silicon on insulator (SOI) technology refers to the use of a
layered silicon-insulator-silicon substrate in place of
conventional silicon substrates in semiconductor
manufacturing, especially microelectronics, to
reduce parasitic device capacitance, thereby improving
performance.
REASONS FOR SOI:
•Replacement for SOS
•Need to extend Moore’s
Law
•Commercial Availability of
SOI wafers

14.  High bit rate
transmission must be
matched by switching
capacity
 Optical or Photonic
switching can provide
such capacity
Switching is the process by
which the destination of a
individual optical information
signal is controlled

15.  The present technology for silicon-based MOEMS and some
future telecommunications applications.
 The key to new developments in optical MEMS is to
successfully apply the underlying physics and develop cost-
effective processing to make high- precision components.
 SOI technology, whereby low stress mirrors and other
MEMS components are made with reproducible mechanical
properties and excellent control of planarity.
 Low stress Si3N4 which has a high Young's modulus and has
promising applications in packaging .
 the necessary precision for optical MEMS can be obtained in
a manufacturable way.
 The combination of Porous Si and MOEMS opens the door
for a new generation of silicon compatible optical
interconnects.

16.  The VLSI technology and micro electro
mechanical devices will have a profound
impact on society as a whole.
 The need of the time is that government
organization must come forward to interact
various micro devices that are being
developed.