**1.2.1 EUV open-frame exposure system (EUVES-7000)**

This equipment uses an electrodeless Z-pinch discharge-excitation plasma light source [9] manufactured by Energetiq Technology Inc. It extracts 13.5 nm light using a Zr filter and multilayer reflecting mirrors. The exposure pattern is a 10 mm x 10 mm open frame; 12 exposures can be achieved per wafer at varying exposure doses. Fig. 3 gives an external view of this equipment and a picture of an exposure pattern (after exposure, PEB, and development).

The plasma emissions produced by the EQ-10M pass through the Zr filter to remove UVregion rays. Next, the Mo-Si multilayer reflector selectively reflects only 13.5 nm rays, which are shaped by the aperture into a 10 mm x 10 mm exposure region. The rotary Mo-Si multilayer reflector directs the light at a reflection angle of 45 degrees toward the exposure chamber at the upper section of the equipment during the exposure of a substrate. For power measurements, it rotates and directs the light to the power measurement diode chamber at the lower section of the equipment. Exposures are performed as the wafer rotates. A total of 12 exposures are possible per wafer at varying exposure doses.

Approach to EUV Lithography Simulation 171

Argon gas mass-flow for protection of mirrors

Following the exposure, a wafer is processed for PEB. Then, following measurement of film thickness, this resist development analyzer is used to measure the development rate of a

The obtained development rate data file is imported into the Prolith lithography simulator

We investigated the sensitivity of positive- and negative-type resists in EUV exposures with the system as described above, then performed simulations using the development rate data

The negative-type resists examined were the SAL-601 electron beam resist and SU-8 epoxyresin-base chemically amplified resist. The positive-type resists used in our experiment were ZEP-520 non-chemically amplified electron beam resist, EUVR-1 and EUVR-2 acrylic-resin-

Fig. 4 is a picture of the beam line.

Rotary exposure chamber

Fig. 4. Beam line for EUV exposure

Diode chamber for power measurement unit

Rotary spectral mirror

**1.3 Experiment and results** 

obtained.

**1.2.2 Resist development analyzer (RDA-800EUV)** 

resist corresponding to each exposure dose [10].

**1.2.3 EUV lithography simulator (Prolith Ver. 9.3)** 

[11] (manufactured by KLA-Tencor) for EUV lithography simulation.

Table 2 gives the conditions of the resists in our experiment.

base resists, and EUVR-3 low-molecular-weight resist.

(a)

Fig. 3. (a) External view of EUVES-7000 and (b) exposure pattern

(a)

(b)

Fig. 3. (a) External view of EUVES-7000 and (b) exposure pattern

Fig. 4 is a picture of the beam line.

Fig. 4. Beam line for EUV exposure
