Specific Process Knowledge/Lithography

From LabAdviser

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There are four different types of lithography available at DTU Nanolab:


Comparing lithography methods at DTU Nanolab

UV Lithography DUV Stepper Lithography E-beam Lithography Nano Imprint Lithography
Generel description Pattern transfer via UltraViolet (UV) light Pattern transfer via Deep UltraViolet (DUV) light Patterning by electron beam Pattern transfer via hot embossing (HE)
Pattern size range
  • Resist type, thickness, and pattern dependent
  • ~0.6 µm and up
  • pattern type, shape and pitch dependent
  • ~200 nm and up
  • ~12 nm - 1 µm (and larger at high currents)
  • ~20 nm and up
Resist type
  • UV sensitive:
    • AZ 5214E, AZ 4562, AZ MiR 701 (positive)
    • AZ 5214E, AZ nLOF 2020, SU-8 (negative)
  • DUV sensitive
    • JSR KRF M230Y, JSR KRF M35G (positive)
    • UVN2300-0.8 (negative)
  • E-beam sensitive
    • AR-P6200 CSAR, ZEP502A , PMMA (positive)
    • HSQ, mr-EBL, AR-N 7520 (negative)
  • Imprint polymers:
    • Topas
    • PMMA
    • mr-I 7030R
Resist thickness range

~0.5µm to 200µm

~50nm to 2µm

~30nm to 1 µm

~ 100nm to 2µm

Typical exposure time

10s-3min pr. wafer using mask aligners.

10min-5hours pr. wafer using maskless aligners.

Process depended, depends on pattern, pattern area and dose.

Throughput is up to 60 wafers/hour.

Depends on dose, Q [µC/cm2], beam current, I [A], and pattern area, A [cm2]:

t = Q*A/I

Process depended, depends also on heating and cooling temperature rates

Substrate size
  • small samples, down to 3x3 mm2
  • 50 mm wafers
  • 100 mm wafers
  • 150 mm wafers
  • 200 mm wafers
  • 100 mm wafers
  • 150 mm wafers
  • 200 mm wafers

We have cassettes that fit to

  • 4 small samples (slit openings: 20mm, 12mm, 8mm, 4mm)
  • 6 wafers of 50 mm in size
  • 3 wafers of 100 mm in size
  • 1 wafer of 150 mm in size
  • 1 wafer of 200 mm in size

Only one cassette can be loaded at a time

  • small samples
  • 50 mm wafers
  • 100 mm wafers
  • 150 mm wafers
Allowed materials
  • Any standard cleanroom material
  • Any standard cleanroom material
  • Any standard cleanroom material, except materials that will degas and special treatment for graphene
  • Any standard cleanroom material


Equipment Pages

Resist

Pretreatment

Coating

Baking

UV Exposure

Deep-UV Exposure

Electron Beam Exposure

NanoImprint Lithography


Development

Descum

Lift-off

Strip


Lithography Tool Package Training

DTU Nanolab offers a Tool Package Training in Lithography; the course includes theory on lithographic processes and equipment, as well as training in equipment operation and processing in the cleanroom.

The course is for all users that intend to perform any kind of lithographic processing in the cleanroom, and is a prerequisite for training in other lithography equipment.


For details, dates, and course material, please check the course description under Courses.


Lithography Tool Package Training
Schedule

Theoretical part

  • Lecture videos that can be viewed at one's leisure.
  • A 1 hour "questions and exercises" session 2 times a month (typically Fridays 09:30-10:30).

Practical part

  • A 3-4 hour training session 2 times a month, max. 4 persons per session (typically Wednesdays 09:00 - 12:30 or 10:00 - 13:30).
  • This part is not mandatory, and may be replaced by individual trainings if relevant.
Location

Theoretical part

  • The location of the "questions and exercises" session is room 121A in building 345C.

Practical part

  • The training session takes place inside the cleanroom. The meeting point will be in front of the first equipment.
Qualified Prerequisites
  • Cleanroom safety course at DTU Nanolab
  • Admission to the cleanroom must be obtained before the training session
  • Theoretical part must be completed before the training session
Preparations

Before the "questions and exercises" session

  • Read Sami Franssila "Introduction to Microfabrication" (2010), Chapter 9: Optical Lithography. (Available online from DTU campus)
  • Watch the lecture videos (7 videos, 2:41 hours in total). Write down any questions that may arise during the videos.

Before training session

  • Complete the theoretical part (Q&E)
  • Watch the training videos of spin coating (automatic), exposure (operation, and alignment), and development (automatic).
  • Study the equipment manuals. The manuals are available in LabManager.
  • Study the TPT process flows (first print, and alignment).
Course Responsible

The Lithography Group at DTU Nanolab lithography@nanolab.dtu.dk.

Learning Objectives
  • Describe fundamental parts of lithographic processing in a cleanroom, design of process flows
  • Authorization to use spin coater, mask aligner, and developer at DTU Nanolab
  • Calculate relevant process parameters
  • Analyze and apply your results of lithographic processing



Knowledge and Information about Lithography

Literature


Lecture videos

  • Lithography TPT lecture videos (7 videos, 2:41 hours in total) on YouTube
  • A full lecture series from a UT Austin course on microfabrication by "litho guru" Chris Mack. Half of the lectures are on (projection) lithography :-)


Lithography TPT lecture slides

Training videos

Playlists on YouTube:


Manuals


Process Flows


Resists


UV Exposure


Electron Beam Exposure


Deep-UV Exposure