#4 (Oct. 22) Photolithgraphy
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#4 (Oct. 22) Photolithgraphy hat is photolithgraphy? hin-film patterning using phtolithgrap pplications of photolithgraphy rends in minimum pattern sizes
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#4 (Oct. 22) Photolithgraphy. -What is photolithgraphy? -Thin-film patterning using phtolithgraphy -Applications of photolithgraphy -Trends in minimum pattern sizes. What Is Photolithgraphy?. Photo + Lithograph Technologies to replicate patterns on a photomask to - PowerPoint PPT Presentation
Transcript of #4 (Oct. 22) Photolithgraphy
#4 (Oct. 22) Photolithgraphy
-What is photolithgraphy?-Thin-film patterning using phtolithgraphy-Applications of photolithgraphy-Trends in minimum pattern sizes
What Is Photolithgraphy?Photo + LithographTechnologies to replicate patterns on a photomask to substrates or thin films on the substrates by using photo-chemical reaction photoresist
Photomask Thin film on a substrate
What Is Photoresit
A material that changes its solubility to developer by irradiation of light (ultraviolet or X ray) and electron beam
Changes:(1) Non-soluble to solvable (positive-type photoresist)(2) Soluble to non-soluble (negative-type photoresist)
Composition of Photoresist
Sensitizer
Change of Sensitizer by UV Irradiation
Non-soluble Soluble
Purposes and Features of Photolithography
Purposes-Fabrication of electron devices such as LSIs-Fabrication of micromachines-Packaging of LSIs and micromachines
Features-Minimum size of 1 m or less is achievable-Batch process-Pattern repetition
a
Photoresist （ 1 m ）
Chromium thin film（ 50 nm)
Fused-quartz substrate (1 mm)
ba b
Photomask Fabrication (1)Chromium thin film deposition and
photoresist deposition
Electron beam
a ba b
Photomask Fabrication (2)
a ba b
Photomask Fabrication (3)
Development
a ba b
Photomask Fabrication (4)
Etching of chromium thin film
a ba b
Photomask Fabrication (5)
Photoresisit removal
Silicon substrate
a ba b
Phtolithography of Al Thin Film (1)
SiO2thin film(1 m)
a ba b
Phtolithography of Al Thin Film (2)
Al thin film（ 1 m)
a ba b
Phtolithography of Al Thin Film (3)
Photoresist
a ba b
Phtolithography of Al Thin Film (4)
Followed by pre-baking at 120 ℃
Mercury lampPhotomask
a ba b
Phtolithography of Al Thin Film (5)
Wavelength (nm)
Inte
nsi
ty (
rela
tive
)
Emission Spectrum of Mercury Lamp
a ba b
Phtolithography of Al Thin Film (6)
Development
Followed by post-baking at 120~180 ℃
a ba b
Phtolithography of Al Thin Film (7)
Al thin film etching
a ba b
Phtolithography of Al Thin Film (8)
Photoresist removal
a ba
Photoresist
Lift-Off of Al Thin Film (1)
b
(2)
Mercury lampPhotomask
a ba b
Lift-Off of Al Thin Film (2)
a ba b
Lift-Off of Al Thin Film (3)
Development
a ba b
Lift-Off of Al Thin Film (4)
(5)
a ba b
Lift-Off of Al Thin Film (5)
a ba b
Lift-Off of Al Thin Film (6)
Wiring Using Al Thin Films
Contact holes
Cross-Section of CMOS LSI
Electron beam scanner
ReticlePhotomask
Stepper
Pattern generator Stepper
Pattern Size Reduction by Stepper
WaferDesign data
Contact aligner
Projection aligner
Stepper
http://www.tochigi-nikon.co.jp/business/stepper/
Trends in Minimum Pattern Size
http://public.itrs.net/
Inside Clean Room (MIT)
by Richard P. Feynman
http://www.zyvex.com/nanotech/feynman.html
There's Plenty of Room at the BottomAn Invitation to Enter a New Field of Physics
Homework: Read This Article by 11/4
