Abstract
Many devices, such as lateral spin valves, depend critically on the quality of interfaces formed between different materials, and hence require the entire device to be fabricated within an ultra-high vacuum environment. This is possible using angled deposition with a suspended mask such that, by depositing from specific angles, different patterns form on the substrate beneath. We use a bi-layer of MMA(8.5)-MAA copolymer and PMMA patterned by electron-beam lithography (EBL) to form such a mask. It is necessary, though, to perform proximity effect correction (PEC) in EBL to achieve the correct spatial distribution of electrons, and hence produce the desired pattern in the developed resist. For bi-layer processes this is a three-dimensional (3D) correction since we must optimise for two different critical doses (one for the copolymer, the other for the PMMA) at defined 3D positions within the resist stack. We perform this 3D correction using the commercial software BEAMER produced by GenISys GmbH. We show that by applying manual shape segregation and modulation to the exposure pattern, prior to the "3DPEC" algorithm, it is possible to achieve much higher contrasts in the spatial distribution of absorbed energy and hence significantly increase the processing window, and yield in the fabrication of suspended masks.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 5-10 |
| Number of pages | 6 |
| Journal | Microelectronic Engineering |
| Volume | 143 |
| DOIs | |
| State | Published - Aug 1 2015 |
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Keywords
- 3D-PEC
- Angled evaporation
- E-beam lithography
- GenISys beamer
- Lateral spin valve
- Suspended shadow mask
Cite this
High contrast 3D proximity correction for electron-beam lithography : An enabling technique for the fabrication of suspended masks for complete device fabrication within an UHV environment. / Rosamond, Mark C.; Batley, Joseph T.; Burnell, Gavin; Hickey, Bryan J.; Linfield, Edmund H.
In: Microelectronic Engineering, Vol. 143, 01.08.2015, p. 5-10.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - High contrast 3D proximity correction for electron-beam lithography
T2 - An enabling technique for the fabrication of suspended masks for complete device fabrication within an UHV environment
AU - Rosamond, Mark C.
AU - Batley, Joseph T.
AU - Burnell, Gavin
AU - Hickey, Bryan J.
AU - Linfield, Edmund H.
PY - 2015/8/1
Y1 - 2015/8/1
N2 - Many devices, such as lateral spin valves, depend critically on the quality of interfaces formed between different materials, and hence require the entire device to be fabricated within an ultra-high vacuum environment. This is possible using angled deposition with a suspended mask such that, by depositing from specific angles, different patterns form on the substrate beneath. We use a bi-layer of MMA(8.5)-MAA copolymer and PMMA patterned by electron-beam lithography (EBL) to form such a mask. It is necessary, though, to perform proximity effect correction (PEC) in EBL to achieve the correct spatial distribution of electrons, and hence produce the desired pattern in the developed resist. For bi-layer processes this is a three-dimensional (3D) correction since we must optimise for two different critical doses (one for the copolymer, the other for the PMMA) at defined 3D positions within the resist stack. We perform this 3D correction using the commercial software BEAMER produced by GenISys GmbH. We show that by applying manual shape segregation and modulation to the exposure pattern, prior to the "3DPEC" algorithm, it is possible to achieve much higher contrasts in the spatial distribution of absorbed energy and hence significantly increase the processing window, and yield in the fabrication of suspended masks.
AB - Many devices, such as lateral spin valves, depend critically on the quality of interfaces formed between different materials, and hence require the entire device to be fabricated within an ultra-high vacuum environment. This is possible using angled deposition with a suspended mask such that, by depositing from specific angles, different patterns form on the substrate beneath. We use a bi-layer of MMA(8.5)-MAA copolymer and PMMA patterned by electron-beam lithography (EBL) to form such a mask. It is necessary, though, to perform proximity effect correction (PEC) in EBL to achieve the correct spatial distribution of electrons, and hence produce the desired pattern in the developed resist. For bi-layer processes this is a three-dimensional (3D) correction since we must optimise for two different critical doses (one for the copolymer, the other for the PMMA) at defined 3D positions within the resist stack. We perform this 3D correction using the commercial software BEAMER produced by GenISys GmbH. We show that by applying manual shape segregation and modulation to the exposure pattern, prior to the "3DPEC" algorithm, it is possible to achieve much higher contrasts in the spatial distribution of absorbed energy and hence significantly increase the processing window, and yield in the fabrication of suspended masks.
KW - 3D-PEC
KW - Angled evaporation
KW - E-beam lithography
KW - GenISys beamer
KW - Lateral spin valve
KW - Suspended shadow mask
UR - http://www.scopus.com/inward/record.url?scp=84922156118&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84922156118&partnerID=8YFLogxK
U2 - 10.1016/j.mee.2015.01.020
DO - 10.1016/j.mee.2015.01.020
M3 - Article
AN - SCOPUS:84922156118
VL - 143
SP - 5
EP - 10
JO - Microelectronic Engineering
JF - Microelectronic Engineering
SN - 0167-9317
ER -