1. By:
Udayasri Jandhyala
Kanchan Joshi
03/18/2003
ME Prof. Furman

2. By:
Udayasri Jandhyala
Kanchan Joshi
03/18/2003
ME Prof. Furman

3. EUVL: Lithography at extreme UV wavelengths is called EUVL.
Lithography: A basic photographic process that allows more features to be crammed onto a computer chip.
EUVL: Lithography at extreme UV wavelengths is called EUVL.
Lithography Process: Light is directed onto a mask-a sort of stencil of an integrated circuit pattern and the image of that pattern is then projected onto a semiconductor wafer covered with light sensitive photoresist.
Present: Current lithography techniques use deep ultraviolet range 248nm wavelengths to print 150 to 120nm size features.
Future is EUVL: Creating smaller features requires wavelengths in the Extreme Ultraviolet range. Light at Extreme Ultraviolet wavelengths is absorbed instead of transmitted by lenses.
Industry Developments: LLNL has developed multilayer coatings capable of reflecting nearly 70% of EUV light at a wavelength of 13.4nm that can be used to fabricate structures with a smaller minimum feature size 50nm.
03/18/2003
ME Prof. Furman

4. 03/18/2003
ME Prof. Furman

5. Micro Exposure tool (MET):
A two-mirror camera which is capable of printing 30nm features.
Functional Requirements:
Low distortion support of the optics
Precision adjustments for aligning the optics
Dimensional stability,both long term-alignment and short term-image placement
03/18/2003
ME Prof. Furman

6. The support ring provides upper and lower kinematic mounting interfaces available to MET.
The support ring has a 360 degrees rotational interface to the M2 cell for the clocking adjustment and it provides attachment points for six actuation flexures.
The triangular shaped M1 cell attaches to the opposite ends of the actuation flexures and together they provide high resolution adjustment in 5 dof critical for optical alignment.
Why Flexures:
Strain attentuation
The function of actuation flexure is to provide a single,adjustable constraint along its axis. It is remotely actuated during alignment process but otherwise functions as a passive constraint.
The M1 and M2 cells each support three flexures that combine to constrain 6dof for each optic.
The support ring, actuation flexures etc are manufactured from Super Invar (a low CTE alloy).
03/18/2003
ME Prof. Furman

7. Actuation System: The actuation flexures support and move the M1 cell relative to the support ring (often called a Stewart platform).
All six members are required to provide rigid constraint and any pure motion of the stage requires coordinated motion of all six flexures.
A number of factors are considered and balanced in the design of actuation flexure.
It must provide stiff axial constraint, sufficient compliance and range of motion in the non constraint directions, low actuation force.
03/18/2003
ME Prof. Furman

8. Projection Optic Mount:
Objective:
Kinematic Constraint
Optic Cell
Bipod Flexure
Optic
03/18/2003
ME Prof. Furman

9. 3DOF Blade Flexure: l z x w y Blade thk=t l=10*t w=l Tx Ty Tz Rx Ry RzS F
Properties
Material
Super Invar 32-5
CTE, linear 20 ºC
0.19 μm/m- ºC
CTE, linear 250 ºC
2.5 μm/m- ºC
03/18/2003
ME Prof. Furman

10. 4DOF Bipod Flexure: Features: Blades in series to add compliances
Equivalent to a sphere and a vee
Connect-disconnect function
Repeatable forces on optic z Tx Ty Tz Rx Ry Rz S F x y
03/18/2003
ME Prof. Furman

11. The final assembly: Mechanical assembly Precision Accuracy 03/18/2003
ME Prof. Furman