Photoresist
Photoresist Photoresist
Contrast (γ) curves: a way to characterize resist Procedure for determining i contrast: 1) spin coat a layer of PR 2) Measure PR thickness 3) Expose for short period of time, Exp. dose = Intensity * t exp Units: mJ/cm 2 4) Immerse wafer in developer for fixed time 5) Rinse and measure remaining resist Assuming positive resist and short exposure time, very little of the PAC has changed to be soluble in the developer so resist thickness is nearly the same as original thickness. Repeat experiment for increasingly larger doses and obtain a contrast curve by plotting resist thickness versus log of incident dose.
Contrast, γ , is the slope of the line at the steepest part of the curve, D o is the lowest energy needed to begin the photochemical reactions, D 100 is the energy for which all resist is removed Low exposure region Opposite behavior because resist is insoluble in developer High exposure region Figure 8.7 Contrast curves for idealized resists: (A) postitive tone and (B) negative tone.
- Page 1 and 2: Chapter 8 Photoresists
- Page 3 and 4: Photoresists (PR) or resists Three
- Page 5 and 6: Substitute: Methyl group Chlorine A
- Page 7 and 8: Positive resist In i-line and g-lin
- Page 9: Light, water are the main drivers o
- Page 13 and 14: Figure 8.9 Typical process flow in
- Page 15 and 16: Industrial systems are called “co
- Page 17: Exposing resist over topology cause
Contrast, γ , is the slope of the line at the steepest part of the curve,<br />
D o is the lowest energy needed to begin the photochemical<br />
reactions, D 100 is the energy for which all resist is removed<br />
Low exposure region<br />
Opposite behavior because resist<br />
is insoluble in developer<br />
High exposure region<br />
Figure 8.7 Contrast curves for idealized resists: (A) postitive tone and (B) negative tone.
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