Michael quirk_半导体制造技术-第15章_光刻_光刻胶显影和先进的光刻技术

Develop
• • • •
Negative Resist Positive Resist Development Methods Resist Development Parameters
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by Michael Quirk and Julian Serda
by Michael Quirk and Julian Serda
(d) Spin dry
Figure 15.7 © 2001 by Prentice Hall
Resist Development Parameters • • • • • • • Developer Temperature Developer Time Developer Volume Normality Rinse Exhaust Flow Wafer Chuck
by Michael Quirk and Julian Serda
Figure 15.4
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Development of Positive Resist
Resist exposed to light dissolves in the develop chemical.
by Michael Quirk and Julian Serda
Figure 15.3
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Negative Resist Crosslinking
UV
Exposed resist
Crosslinks Unexposed resist
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Eight Basic Steps of Photolithography
Chapter Covered 13 13 13 14 15 15 15 15
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Figure 15.1
© 2001 by Prentice Hall
Reduction of Standing Wave Effect due to PEB
Puddle Resist Development
Puddle formation Developer dispenser
(a) Puddle dispense
(b) Spin-off excess developer
(c) DI H2O rinse
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• Resist Hardening with Deep UV
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Softened Resist Flow at High Temperature
PAC
(c) PEB causes PAC diffusion
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(d) Result of PEB
Figure 15.2 © 2001 by Prentice Hall
© 2001 by Prentice Hall
Photoresist Development Problems
Resist Substrate
X
X

X
Under develop
Incomplete develop
Correct develop
Severe overdevelop
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Load Station
Vapor Prime
Resist Coat
Spray DevelopRinse
Edge-bead Removal Transfer Station
Wafer Transfer System
To vacuum pump Soft Bake Cool Plate Cool Plate Hard Bake Vacuum chuck Spindle connected to spin motor
Standing waves
PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC
Unexposed photoresist
PAC PAC PAC PAC PAC
Exposed photoresist
Step 1. Vapor prime 2. Spin coat 3. Soft bake 4. Alignment and exposure 5. Post-exposure bake 6. Develop 7. Hard bake 8. Develop inspect
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Hard Bake • Characteristics of Hard Bake:
– Post-Development Exposure
(a) Wafer track system
(b) Developer spray dispenser
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Figure 15.6
© 2001 by Prentice Hall
Semiconductor Manufacturing Technology
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Amine Contamination of DUV Resist leading to “T-top” Formation
Unexposed positive resist
Crosslinked resist
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Figure 15.5
© 2001 by Prentice Hall
Development Methods
– Evaporates Residual Solvent in Photoresist
– Hardens the Resist
– Improves Resist-to-Wafer Adhesion – Prepares Resist for Subsequent Processing
– Higher Temperature than Soft Bake, but not to Point Where Resist Softens and Flows
by Michael Quirk and Julian Serda
Table 15.1
© 2001 by Prentice Hall
Post Exposure Bake
• Deep UV Exposure Bake
– Temperature Uniformity – PEB Delay
• Conventional I-Line PEB
PAC
PAC
PAC
PAC PAC PAC PAC PAC PAC
PAC
PAC
PAC
(a) Exposure to UV light
PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC
(b) Striations in resist
PAC
• Continuous Spray Development • Puddle Development
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Βιβλιοθήκη Baidu
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Resist Development with Continuous Spray
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Chapter 15
Photolithography: Resist Development and Advanced Lithography
Photoresist
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by Michael Quirk and Julian Serda
Figure 15.8
© 2001 by Prentice Hall
Develop Inspect • • • • Post-Develop Inspection to Find Defects Find Defects before Etching or Implanting Prevents Scrap Characterizes the Photo Process by Providing Feedback Regarding Quality of the Lithography Process • Develop Inspect Rework Flow
Region of unexposed photoresist
Neutralized photoresist
}
H+ H+
Resist T-topping
H+ PAG H+ H+ H+ PAG
PAG PAG PAG PAG PAG
Development
H+
H+ H+
H+
PAG
Acid-catalyzed reaction of exposed resist (post PEB)
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by Michael Quirk and Julian Serda
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Objectives
After studying the material in this chapter, you will be able to: 1. Explain why and how a post exposure bake is done for conventional and Chemically amplified DUV resist. 2. Describe the negative and positive resist development process for conventional and chemically amplified DUV resist. 3. List and discuss the two most common resist development methods and the critical development parameters. 4. State why a hard bake is done after resist development. 5. Explain the benefits of a post-develop inspection. 6. List and describe the four different alternatives for advanced lithography, including the challenges for introducing each alternative into production. 7. Describe and give the benefit for the advanced resist process of top surface imaging.