SEMICON WEST 2008 - July 15-17, 2008 - Moscone Center - San Francisco -

California - Booth #851

Leuven, Belgium - July 14, 2008 - IMEC, in collaboration with JSR

Corporation, realized a simplified process using only one etch step to

reduce the cost of double patterning. 32nm lines and spaces were printed

with a double exposure/single etch process, effectively freezing the resist

after the first exposure. This simplified process paves the way for an

industrial take-up of double patterning for the 32nm technology node.

Double patterning will be the primary lithography candidate for the 32nm

technology node. But when using two litho and two etch steps, this

technique will be expensive and slow. Therefore, IMEC is developing

alternative process flows that reduce the cost-of-ownership by eliminating

the intermediate etch step and replacing it with a process step in the

litho track.

One way to eliminate the extra etch step is through freezing the resist

after the first exposure. With this technique, IMEC has demonstrated 32nm

node logic patterning. The freezing material used to reach this result has

been developed by JSR Corporation. It prevents the resist from expanding

(i.e. CD growth) or shrinking. And when the second resist layer is added,

the two do not interact. Also, the freezing material is compatible with the

lithography hardware.

The step of freezing the resist is done in the litho track. After exposing

the first pattern, the resist is coated with the freezing material. Next,

the wafer is baked to freeze the resist. Then the excess freezing material

is removed using a developer. In the following step, a second resist layer

is added and the second exposure is done. To prevent the second resist

layer solvent from washing away the first resist, the freezing material

changes the properties of the first resist layer so that it becomes

non-soluble in the second resist layer.

This technique allowed printing 32nm dense lines using dipole illumination

at 1.0NA. CDU for the 44nm HP lines was excellent (3s = 2.4nm). Moreover,

32nm node 2D logic cells as well as 32nm dense lines could be etched into

poly. Lines resulting from the first and second lithography step cannot be

distinguished, illustrating the good resolution obtained with this


IMEC is currently transferring this process to its newly installed 1.35 NA

immersion scanner (ASML XT:1900i) to explore this solution for sub-32nm

half pitches (towards 22nm node).

This news release and pictures can be downloaded at:

About IMEC

IMEC is a world-leading independent research center in nanoelectronics and

nanotechnology. IMEC vzw is headquartered in, has a sister

company in the Netherlands, IMEC-NL, offices in the US, China and Taiwan,

and representatives in Japan. Its staff of more than 1600 people includes

more than 500 industrial residents and guest researchers. In 2007, its

revenue (P&L) was EUR 244.5 million.

IMEC's More Moore research aims at semiconductor scaling towards sub-32nm

nodes. With its More than Moore research, IMEC looks into technologies for

nomadic embedded systems, wireless autonomous transducer solutions,

biomedical electronics, photovoltaics, organic electronics and GaN power


IMEC's research bridges the gap between fundamental research at

universities and technology development in industry. Its unique balance of

processing and system know-how, intellectual property portfolio,

state-of-the-art infrastructure and its strong network worldwide position

IMEC as a key partner for shaping technologies for future systems.

Further information on IMEC can be found at


Katrien Marent, Director of External Communications, T: +32 16 28 18 80,

Mobile : +32 474 30 28 66,

Barbara Kalkis, Maestro Marketing & PR, T: 1 408 996 9975, M: 1 408 529