44 Vol.67 No.42012
SPECIAL REPORTS
KIHARA Naoko
DSADirected Self-Assembly
In recent years, attention has been focused on self-organizing technology as one of the next-generation lithography technologies, because of its ability to form regular nanometer-scale patterns by the application of self-organized diblock copolymers. However, as the self-organizing phenomenon is a physical process, it is necessary to control the alignment of self-assembled patterns for the fabrication of actual circuit patterns of semiconductor devices.
Toshiba has been developing a directed self-assembly (DSA) process that is considered to have the potential to realize sub-10 nm feature size devices using a method combining the photolithographic process and a self-organizing material.
1
2
nmnm10 nm
Directed Self-Assembly Lithography Technology
PS-PMMAAFM
500 nm
AB
1 Image of phase separation of diblock copolymer
45
DSADirected Self-Assembly
2
12nmnmPS-PMMAPolystyrene-Polymethylmethacry-lateAFM1 2PS-
PDMSPolystyrene-PolydimethylsiloxaneSEM3PS30,000PDMS7,500PS-PDMS33 nmPS-PDMSPS11,700PDMS2,90017 nm
3
3.1
4ArF
B A
2 ABChange of typical structures of A-B diblock copolymers
100 nm 100 nm
PS30,000PDMS7,500
PS11,700PDMS2,900
3 Dependence of molecular weight of polystyrene-polydimethylsiloxane (PS-PDMS) on self-organization pitch
4 Substrate patterning process using diblock copolymer template
46 Vol.67 No.42012
DSADSA
3.2
AFM516 nm
10010nm1
3.366AAA
4DSA
4.1714.2
100 nm
100 nm
5DSA using graphoepitaxy method
A
A
B
6DSA using chemical epitaxy method
47
DSA8
ABBB
5
DSADSADSA
Stoykovich, M. P. et al. Directed assembly of block copolymer blends into
nonregular device-oriented structure. Science. 308, 2005, p.14421446. Sanders, D. P. et al. Integration of direcred self-assembly with 193 nm
lithography. Journal of Photopolymer Science and Technology. 23, 2010, p.1118.
KIHARA Naoko Storage Materials & Devices Lab.
A B
B
8DSAShrinkage of hole patterns using DSA
A
A
B
71Shrinkage of line and space (L&S) pitch using chemical epitaxy method
