Wafer Fabrication Part II - NECTECtmec.nectec.or.th/.../research/ic_fabrication_en.pdf · 4 Wafer Fabrication Processes CMOS Process Bipolar Process BiCMOS Process Technologie 0.25µm

Wa fe r F a b ric a tio n P a rt II

22

Introduction to Wafer Fabrication

• Introduction to TMEC• History from Edison’s Light Bulb to Pentium 4• Semiconductor Materials • Wafer Preparation• Wafer Fabrication Processes• Thin Film Deposition Process• Patterning Process• Etching Process• Doping Process• Contamination

33

Microelectronics Fabrication

Lithography

Etching

Doping

Thin Film Deposition

44

Wafer Fabrication Processes

CMOS Process Bipolar Process

BiCMOS Process

Technologie 0.25µm BiCMOS SiGe,Philips

55

CMOS Process Flow

p-type Silicon Substrate

1. Starting wafer2. n-well3. Active4. Gate5. Junction6. ILD7. Contacts and metal 18. Vias and metal 29. Passivation

66

Wafer

p-type Cz wafer

p-type

77

Process flow

p-type Silicon Substrate

1. Starting wafer2. n-well3. Active4. Gate5. Junction6. ILD7. Contacts and metal 18. Vias and metal 29. Passivation

88

Initial oxidation: O2/H2 (Thickness: 420 nm)

p-type

n-well

SiO2

99

n-well

Photolithography : NWELL

p-type

Photoresist (PR)

1010

n-well

Dry etch oxide

p-type

1111

n-well

n-well implantation : Phosphorus (3x1012 cm-3, 100 keV)

p-type

1212

Resist strip

p-type

n-well

1313

n-well drive : Anneal : N2

Differential Oxidation : O2/H2 Anneal : N2

p-type

n-well

n-well

1414

Process flow

p-type Silicon Substrate

1. Starting wafer2. n-well3. Active4. Gate5. Junction6. ILD7. Contacts and metal 18. Vias and metal 29. Passivation

1515

Active

Wet etch all oxide + Pad oxidation (20 nm)

p-type

n-well

1616

Deposition : Nitride (150 nm)

p-type

n-well

Active

1717

Photolithography : ACTIVE

p-type

n-well

Active

1818

Dry etch nitride

p-type

n-well

Active

1919

Resist strip

p-type

n-well

Active

2020

Photolithography : NFIELD

p-type

n-well

Active

2121

NField implantation : Boron (8x1013 cm-3, 60 keV)

p-type

n-well

Active

2222

Resist strip

p-type

n-well

Active

2323

Field oxidation : O2/H2

p-type

n-well

Active

2424

Active

Wet etch Nitride

p-type

n-well

Active

2525

Process flow

p-type Silicon Substrate

1. Starting wafer2. n-well3. Active4. Gate5. Junction6. ILD7. Contacts and metal 18. Vias and metal 29. Passivation

2626

Gate

Etch Pad oxide + WR oxidation : H2/O2 (50 nm)

p-type

n-well

2727

Photolithography : NFIELD

p-type

n-well

Gate

2828

APT Implantation : Boron (6.5x1011 cm-3, 110 keV)

p-type

n-well

Gate

2929

Resist strip

p-type

n-well

Gate

3030

Anneal : N2

p-type

n-well

Gate

3131

Etch WR oxide + Gate oxidation (25 nm)

p-type

n-well

Gate

3232

VTA implantation : Boron (8x1011 cm-3, 20 keV)

p-type

n-well

Gate

3333

Poly deposition

p-type

n-well

Gate

3434

TEOS deposition

p-type

n-well

Gate

3535

Poly implantation : Phosphorus (1.2x1016 cm-3, 50 keV)

p-type

n-well

Gate

3636

Anneal : N2

p-type

n-well

Gate

3737

Wet etch TEOS

p-type

n-well

Gate

3838

Photolithography : POLY

p-type

n-well

Gate

3939

Dry etch poly

p-type

n-well

Gate

4040

Resist strip

p-type

n-well

Gate

4141

Process flow

p-type Silicon Substrate

1. Starting wafer2. n-well3. Active4. Gate5. Junction6. ILD7. Contacts and metal 18. Vias and metal 29. Passivation

4242

Junctions

Oxidation : O2

p-type

n-well

4343

Photolithography : NPLUS

p-type

n-well

Junctions

4444

Nplus implantation : Phosphorus (1014 cm-2, 70 keV)Arsenic (6x1015 cm-2, 130 keV)

p-type

n-well

Junctions

4545

Resist strip

p-type

n-well

Junctions

4646

Photolithography : PPLUS

p-type

n-well

Junctions

4747

Pplus implantation :Boron (5x1015 cm-2, 20 keV)

p-type

n-well

Junctions

4848

Resist strip

p-type

n-well

Junctions

4949

Coat front + Backside etch

p-type

n-well

Junctions

5050

Resist strip

p-type

n-well

Junctions

5151

Rapid thermal anneal : N2

p-type

n-well

Junctions

5252

Process flow

p-type Silicon Substrate

1. Starting wafer2. n-well3. Active4. Gate5. Junction6. Interlayer Dielectric (ILD)7. Contacts and metal 18. Vias and metal 29. Passivation

5353

Interlayer Dielectric

TEOS deposition : UTEOS

p-type

n-well

5454

SOG coatSOG cureSOG coatSOG Cure

p-type

n-well

Interlayer Dielectric

5555

PSG depositionPSG densification

p-type

n-well

Interlayer Dielectric

5656

Coat frontBackside etch

p-type

n-well

Interlayer Dielectric

5757

Resist strip

p-type

n-well

Interlayer Dielectric

5858

Process flow

p-type Silicon Substrate

1. Starting wafer2. n-well3. Active4. Gate5. Junction6. ILD7. Contacts and metal 18. Vias and metal 29. Passivation

5959

Contacts and Metal1

Photolithography : CONTACT

p-type

n-well

6060

Dry etch contacts : isotropic + anisotropic

p-type

n-well

Contacts and Metal1

6161

Resist strip

p-type

n-well

Contacts and Metal1

6262

Contract cleanMetal 1 sputtering : TiTiN

AlSiCu TiN

p-type

n-well

Contacts and Metal1

6363

Photolithography : METAL1

p-type

n-well

Contacts and Metal1

6464

Dry etch Metal 1

p-type

n-well

Contacts and Metal1

6565

Resist strip

p-type

n-well

Contacts and Metal1

6666

Process flow

p-type Silicon Substrate

1. Starting wafer2. n-well3. Active4. Gate5. Junction6. ILD7. Contacts and metal 18. Vias and metal 29. Passivation

6767

Via and Metal2

Plasma oxide deposition

p-type

n-well

6868

SOG coatSOG cure

p-type

n-well

Via and Metal2

6969

Plasma oxide deposition

p-type

n-well

Via and Metal2

7070

Photolithography : VIA

p-type

n-well

Via and Metal2

7171

Dry etch vias : isotropic + anisotropic

p-type

n-well

Via and Metal2

7272

Resist strip

p-type

n-well

Via and Metal2

7373

Metal2 sputtering : AlsiCu TiN

p-type

n-well

Via and Metal2

7474

Photolithography : METAL2

p-type

n-well

Via and Metal2

7575

Dry etch metal2

p-type

n-well

Via and Metal2

7676

Resist strip

p-type

n-well

Via and Metal2

7777

Process flow

p-type Silicon Substrate

1. Starting wafer2. n-well3. Active4. Gate5. Junction6. ILD7. Contacts and metal 18. Vias and metal 29. Passivation

7878

Passivation

PECVD nitride deposition, Photolithography : PASS, Dry etch nitride, Resist strip, Sintering : Forming gas

p-type

n-well