The process for creating Electronic Images and Patterns

1. Photo-LithographyPhoto-Lithography
John GlenningJohn Glenning
September, 2013September, 2013
© 2013 John Glenning© 2013 John Glenning

2. Photo-LithographyPhoto-Lithography
Photolithography: The process of transferring geometric shapes on a mask to a surface
© 2013 John Glenning© 2013 John Glenning

3. Photo-LithographyPhoto-Lithography
Photolithography: The process of transferring geometric shapes on a mask to a surface
Light is used to transfer a pattern from a photo-mask to a light sensitive chemical
commonly referred as a photoresist.
© 2013 John Glenning© 2013 John Glenning

4. Photo-LithographyPhoto-Lithography
Photolithography: The process of transferring geometric shapes on a mask to a surface
Light is used to transfer a pattern from a photo-mask to a light sensitive chemical
commonly referred as a photoresist.
The process is done in a “cleanroom” because particulate contamination can cause
voids to be created in the material. This is dependent on the size of the particle and
thickness that is being etched.
© 2013 John Glenning© 2013 John Glenning

5. Photo-LithographyPhoto-Lithography
Photolithography: The process of transferring geometric shapes on a mask to a surface
Light is used to transfer a pattern from a photo-mask to a light sensitive chemical
commonly referred as a photoresist.
The process is done in a “cleanroom” because particulate contamination can cause
voids to be created in the material. This is dependent on the size of the particle and
thickness that is being etched.
This process is followed by an etching process or a deposition process.
© 2013 John Glenning© 2013 John Glenning

6. Photo-LithographyPhoto-Lithography
Photolithography: The process of transferring geometric shapes on a mask to a surface
Light is used to transfer a pattern from a photo-mask to a light sensitive chemical
commonly referred as a photoresist.
The process is done in a “cleanroom” because particulate contamination can cause
voids to be created in the material. This is dependent on the size of the particle and
thickness that is being etched.
This process is followed by an etching process or a deposition process.
A photoresist is exposed to light by projection through a glass that has geometric
patterns.
© 2013 John Glenning© 2013 John Glenning

7. Photo-LithographyPhoto-Lithography
Photolithography: The process of transferring geometric shapes on a mask to a surface
Light is used to transfer a pattern from a photo-mask to a light sensitive chemical
commonly referred as a photoresist.
The process is done in a “cleanroom” because particulate contamination can cause
voids to be created in the material. This is dependent on the size of the particle and
thickness that is being etched.
This process is followed by an etching process or a deposition process.
A photoresist is exposed to light by projection through a glass that has geometric
patterns.
This often followed by photoresist developing, etching, photoresist stripping and
cleaning.
© 2013 John Glenning© 2013 John Glenning

8. Photo-LithographyPhoto-Lithography
Photolithography: The process of transferring geometric shapes on a mask to a surface
Light is used to transfer a pattern from a photo-mask to a light sensitive chemical
commonly referred as a photoresist.
The process is done in a “cleanroom” because particulate contamination can cause
voids to be created in the material. This is dependent on the size of the particle and
thickness that is being etched.
This process is followed by an etching process or a deposition process.
A photoresist is exposed to light by projection through a glass that has geometric
patterns.
This often followed by photoresist developing, etching, photoresist stripping and
cleaning.
The process requires a flat substrate.
© 2013 John Glenning© 2013 John Glenning

9. Photo-LithographyPhoto-Lithography
Cleanrooms:
An environment that has a low level of air-borne contaminants such as dust, bacteria
and chemical vapors.
© 2013 John Glenning© 2013 John Glenning

10. Photo-LithographyPhoto-Lithography
Cleanrooms:
An environment that has a low level of air-borne contaminants such as dust, bacteria
and chemical vapors.
A cleanroom has a controlled level of contamination that is specified by the number of
particles per cubic meter at a specified particle size
© 2013 John Glenning© 2013 John Glenning

11. Photo-LithographyPhoto-Lithography
Cleanrooms:
An environment that has a low level of air-borne contaminants such as dust, bacteria
and chemical vapors.
A cleanroom has a controlled level of contamination that is specified by the number of
particles per cubic meter at a specified particle size
These particles can create voids in the material when they deposit on the artwork.
© 2013 John Glenning© 2013 John Glenning

12. Photo-LithographyPhoto-Lithography
Artwork:
The “artwork”, also known as a mask, needs to be created.
© 2013 John Glenning© 2013 John Glenning

13. Photo-LithographyPhoto-Lithography
Artwork:
The “artwork”, also known as a mask, needs to be created.
The artwork is created on glass that has an acceptably low coefficient of thermal
expansion.
© 2013 John Glenning© 2013 John Glenning

14. Photo-LithographyPhoto-Lithography
Artwork:
The “artwork”, also known as a mask, needs to be created.
The artwork is created on glass that has an acceptably low coefficient of thermal
expansion.
Every product design has to have different artwork.
© 2013 John Glenning© 2013 John Glenning

15. Photo-LithographyPhoto-Lithography
Artwork:
The “artwork”, also known as a mask, needs to be created.
The artwork is created on glass that has an acceptably low coefficient of thermal
expansion.
Every product design has to have different artwork.
Most products have artwork for the front and back of the product to be etched
© 2013 John Glenning© 2013 John Glenning

16. Photo-LithographyPhoto-Lithography
Artwork:
The “artwork”, also known as a mask, needs to be created.
The artwork is created on glass that has an acceptably low coefficient of thermal
expansion.
Every product design has to have different artwork.
Most products have artwork for the front and back of the product to be etched
Artwork is created by sputtering metal on glass, imaged using a photoresist and the
metal is removed (etched) from the area where the light needs to transmit through.
© 2013 John Glenning© 2013 John Glenning

17. Photo-LithographyPhoto-Lithography
Artwork:
The “artwork”, also known as a mask, needs to be created.
The artwork is created on glass that has an acceptably low coefficient of thermal
expansion.
Every product design has to have different artwork.
Most products have artwork for the front and back of the product to be etched
Artwork is created by sputtering metal on glass, imaged using a photoresist and the
metal is removed (etched) from the area where the light needs to transmit through.
If the wrong type of glass is used, the image can “walk” while the glass heats up.
© 2013 John Glenning© 2013 John Glenning

18. Photo-LithographyPhoto-Lithography
Product Manufacturing:
The surface of the material is cleaned using clean water and filtered to remove
particulate contamination.
© 2013 John Glenning© 2013 John Glenning

19. Photo-LithographyPhoto-Lithography
Product Manufacturing:
The surface of the material is cleaned using clean water and filtered to remove
particulate contamination.
The surface is dried.
© 2013 John Glenning© 2013 John Glenning

20. Photo-LithographyPhoto-Lithography
Product Manufacturing:
The surface of the material is cleaned using clean water and filtered to remove
particulate contamination.
The surface is dried.
A photoresist is coated, usually on both sides
© 2013 John Glenning© 2013 John Glenning

21. Photo-LithographyPhoto-Lithography
Product Manufacturing:
The surface of the material is cleaned using clean water and filtered to remove
particulate contamination.
The surface is dried.
A photoresist is coated, usually on both sides
The front and back images need to be properly aligned with in the acceptable tolerances
in the X, Y and Ɵ directions.
© 2013 John Glenning© 2013 John Glenning

22. Photo-LithographyPhoto-Lithography
Product Manufacturing:
The surface of the material is cleaned using clean water and filtered to remove
particulate contamination.
The surface is dried.
A photoresist is coated, usually on both sides
The front and back images need to be properly aligned with in the acceptable tolerances
in the X, Y and Ɵ directions.
Light is then projected onto the photoresist for a sufficient period of time to cross-link the
areas where it is desirable to prevent etching.
© 2013 John Glenning© 2013 John Glenning

23. Photo-LithographyPhoto-Lithography
Product Manufacturing:
The surface of the material is cleaned using clean water and filtered to remove
particulate contamination.
The surface is dried.
A photoresist is coated, usually on both sides
The front and back images need to be properly aligned with in the acceptable tolerances
in the X, Y and Ɵ directions.
Light is then projected onto the photoresist for a sufficient period of time to cross-link the
areas where it is desirable to prevent etching.
The material is etched, the remaining photoresist is “stripped” off and the surface is then
cleaned.
© 2013 John Glenning© 2013 John Glenning

24. Photo-LithographyPhoto-Lithography
End of Presentation
© 2013 John Glenning© 2013 John Glenning