Electronics and Microelectronics AE4B34EM

9. lecture

• IC processing technology

• Wafer fabrication

• Lithography

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

How to get

1 000 000 000

Components to 1 cm2

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

It’s very small world…

Human hair on the surface of the chip

From The Oregonian, April 07, 2008

It’s very small world…

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

More than 2 000 000 transistors in 45nm technology can be integrated on the surface of full stop.

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

Technology process

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

Why is the integration so beneficial?

Improve functionality of the system

Higher speed an performance

Increase whole system reliability

Lower power consumption

Billions of identical electronic components are assembled on one single chip with 100% functionality

Lower Price

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

Basic steps of IC processing

Preparation of single crystal Si wafer

Lithography

Etching

Thermal oxidation or deposition of silicon dioxide

Diffusion

Ion Implantation

Physical, chemical deposition

Epitaxial growth

Packaging and Encapsulating

Testing

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

Clean rooms

In the normal living environment is about 10 million particles in cubic meter. In such an environment would be impossible to manufacture semiconductor devices Fresh air Exhausted

air

Selling filters

Leakage

1 – 100 particles

Overpressure 10-15 Pa

Air velocity 0,5 m/s

Adjustment Temperature

and humidity

Perforated floor

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

Some pictures from IC process

Special clothing, boots, gloves, masks

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

IC Technology Fab

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

IC processing technology - video

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

http://www.youtube.com/watch?v=aWVywhzuHnQ&feature=PlayList&p=

23BCE720D421E520&playnext=1&playnext_from=PL&index=30

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

Preparation of single crystal Si wafers

Single chip

Wafer

Today, we use wafers up to 15" (45 cm) diameter

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

Wafer evolution

Year of invention

1970 1975 1980 1985 1990 1995 2000

75

(44,2) (78,5)

125

150

(176,7)

2005

50

(Surface in cm²) 300

(706,8)

450

(6358)

200

(314,1)

100

(122,5)

5-6

150 mm 4

200 mm 3-4 roky

300 mm

(19,6)

2009: 450 mm

Diameter in mm

Intel Samsung TSMC

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

Wafer fabrication technology

Monocrystal growth

Monocrystal milling

Cutting of the ends

Veneers cut

Wafer cutting

Edge grinding

Grinding and polishing

Etching

Polishing

Testing

Slurry

Polishing table

Polishing head

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

Wafer fabrication technology

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

Wafer fabrication technology

Monocrystal nucleus

Melted Si

Heating

Insulating cap

Monocrystal

Melting pot

Heating

Monocrystal holder and a

rotary mechanism

Czochralsky method – monocrystal growth

Silicon melts at 1415 ° C compared to iron at 1535 ° C, aluminum at 660 º C.

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

Wafer fabrication technology

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

Single crystal Growth unit

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

Single crystal processing

Veneer cutter

Diameter adjustment

Contaminated ends are cut off

Wafer Cutter

Type conductivity (P or N) and crystallographic orientation of silicon are encoded in the relative position of the main

and auxiliary veneers

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

Wafer Polishing

The upper polishing plate

The lower polishing plate

Wafer

Abrasive

material

The surface of the wafer must be perfectly smoothed without any scratches and bumps. Accuracy is at the nanoscale.

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

Wafer polishing unit Wafer processing technology - video

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

http://www.youtube.com/watch?v=LWfCqpJzJYM&feature=P

layList&p=E513A3C80416FA47&index=0&playnext=1

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

Measurement of wafers characteristics

Black points

Half mirror

Light source

Lens

Imaging Optics

Imaging Optics

White points

Lens

The light reflected by the surface heterogeneity

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

The size and properties of wafers

Diameter (mm)

Thickness

(m)

Surface (cm2)

Weight (grams)

150 675 20 176 28

200 725 20 314 53

300 775 20 706 127

400 825 20 1256 241

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

Why we want bigger diameter?

88 chips 200-mm wafer

232 chips 300-mm wafer

We expect the size of microprocessors 1,5 x 1,5 cm

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

Defects in the IC process

• The yield (number of good wafers) corresponds chip size • Chip Price depends on Yield

25% 80%

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

The yield

_ _ _ _ _.100%

_ _ _ _ _

Number of good chips on waferY

Number of all chips on wafer

__

_ _ _

Wafer priceChip price

Number of good chips Y

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

Úlomek křemíku

Lithography process

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

PolySi layer after etching and removal of photoresist.

Photoresist after processing (picture shows a PolySi layer grown on top of SiO2)

How to get the layer topology on the silicon chip…

Lithography is a technique in which selected portions of given layer can be masked out

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

Types of lithography

Types of lithography:

Photolithography

Electron lithography

X-ray lithography

It is one of the factors that affect the density of integration

Photolithography

Electron lithography with direct exposure

X-ray photolithography

| 0,1

| 0,2

| 1,0

| 0,5

| 0,2

| 0,01

| 0,05

| 5

m

DUV

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

Radiation sources in ultraviolet region

l (nm)

700 4 550 600 650 500 450 400 350 300 250 200 150 100 50

Ultra violet region Visible region

Mercury lamp laser

g h i

365 405 248 193 13 436 157 126

Ultraviolet Red Blue Green Yellow Orange Mid-UV EUV DUV VUV

Jiří Jakovenko – Electronics and Microelectronics - Department of Microelectronics – CTU

Oxidation

Optical mask

Next technology step

Photoresist coating

Washing, drying Etching

Photoresist processing

Exposition

Typical operation steps in one photolithographic cycle

Photolithography

photoresist removal