Specific Process Knowledge/Lithography/5214E: Difference between revisions

Latest revision as of 08:20, 13 April 2023

This section, including all images and pictures, is created by DTU Nanolab staff unless otherwise stated.

Feedback to this page: click here

Resist description

AZ 5214E is a positive UV photoresist with image reversal capability. It is considered to have good adhesion when wet etching.

Spin coating

Spin curves for AZ 5214E (old German version) using a 30 s spin-off, and a 60s @ 90°C softbake

Typical spin parameters:

Spin off: 30-60 s
Soft bake: 60 s @ 90°C

Image reversal

Typical image reversal parameters:

Reversal bake temperature: 110°C
Reversal bake time: 60 s
Flood exposure: 500 mJ/cm²

If 5214E is baked after exposure, the exposed resist will cross-link, making it insoluble in the developer. This is called the "Reversal bake". The reversal bake activates cross-linking of the exposed areas, which "reverses" the polarity of the design. When the substrate is flood-exposed after the reversal bake, the previously unexposed areas become soluble, and will be removed in the subsequent development. The image reversal procedure effectively makes AZ 5214E a negative resist.

The image reversal process greatly increases the sensitivity of AZ 5214E, and the dose of the image exposure is a critical parameter, especially if negative angled resist sidewalls are desired.
Half dose of the normal, positive process is a good starting point for optimization. Similarly, the reversal bake is also a critical step, and must be tightly controlled in order to achieve consistent results. If negative sidewalls are desired, 60 - 120 s at 110°C is recommended (as well as a resist thickness above 2 µm), but if straight sidewalls are desired, 60 - 120 s at 120°C can be used.

The flood exposure, on the other hand, is uncritical, and ~5 times the normal positive process dose is generally used.

Development

Development speed:

Puddle development in 2.38% TMAH (AZ 726 MIF): ~2 µm/min

@@ Line 1: / Line 1: @@
+{{:Specific Process Knowledge/Lithography/authors_generic}}
+'''Feedback to this page''': '''[mailto:labadviser@nanolab.dtu.dk?Subject=Feed%20back%20from%20page%20http://labadviser.nanolab.dtu.dk/index.php/Specific_Process_Knowledge/Lithography/5214E click here]'''
+[[Category: Lithography|Resist]]
+[[Category: Resist|AZ 5214E]]
 __TOC__
-AZ 5214E is a positive UV photoresist with image reversal capability.
+==Resist description==
+AZ 5214E is a positive UV photoresist with image reversal capability. It is considered to have good adhesion when wet etching.
 ==Spin coating==
-[[Image:5214Espincurves.JPG|500x500px|thumb|Spin curves for AZ 5214E using a 30s spin-off, and a 60s@90°C softbake]]
+[[Image:5214Espincurves.JPG|500x500px|thumb|Spin curves for AZ 5214E (old German version) using a 30 s spin-off, and a 60s @ 90°C softbake]]
 '''Typical spin parameters:'''
 *Spin off: 30-60 s
-*Soft bake: 60s @ 90°C
+*Soft bake: 60 s @ 90°C
 <br clear="all" />
 ==Image reversal==
-If 5214E is baked after exposure, the exposed resist will cross-link, making it insoluble in the developer. This is called the "Reversal bake", or sometimes the post-exposure bake. The reversal bake activates cross-linking of the exposed areas, which "reverses" the polarity of the design.
+'''Typical image reversal parameters:'''
+*Reversal bake temperature: 110°C
+*Reversal bake time: 60 s
+*Flood exposure: 500 mJ/cm<sup>2</sup>
-If the substrate is flood exposed after the reversal bake, the previously unexposed areas become soluble, and will be removed in the subsequent development. The reversal procedure effectively makes AZ 5214E a negative resist.
+If 5214E is baked after exposure, the exposed resist will cross-link, making it insoluble in the developer. This is called the "Reversal bake". The reversal bake activates cross-linking of the exposed areas, which "reverses" the polarity of the design. When the substrate is flood-exposed after the reversal bake, the previously unexposed areas become soluble, and will be removed in the subsequent development. The image reversal procedure effectively makes AZ 5214E a negative resist.
 The image reversal process greatly increases the sensitivity of AZ 5214E, and the dose of the image exposure is a critical parameter, especially if negative angled resist sidewalls are desired.<br>
-Half dose of the normal, positive process is a good starting point for optimization. Similarly, the reversal bake is also a critical step, and must be tightly controlled in order to achieve consistent results. If negative sidewalls are desired, 60-120s at 110°C is recommended (as well as a resist thickness above 2 µm), but if straight sidewalls are desired, 60-120s at 120°C can be used.
+Half dose of the normal, positive process is a good starting point for optimization. Similarly, the reversal bake is also a critical step, and must be tightly controlled in order to achieve consistent results. If negative sidewalls are desired, 60 - 120 s at 110°C is recommended (as well as a resist thickness above 2 µm), but if straight sidewalls are desired, 60 - 120 s at 120°C can be used.
-The flood exposure, on the other hand, is uncritical, and 2-5 times the normal positive process dose is generally used.
+The flood exposure, on the other hand, is uncritical, and ~5 times the normal positive process dose is generally used.
 ==Development==
-'''Development speed in 2.38% TMAH (AZ 726 MIF):''' ~2 µm/min
+'''Development speed:'''
+*Puddle development in 2.38% TMAH (AZ 726 MIF): ~2 µm/min