Sub-resolution assist features (SRAFs) damage-free cleaning by use of megasonic nozzle becomes main challenge in
photomask industry. Using non-sulfate cleaning tool, the effect of key performance parameters of 1 MHz puddle
megasonic nozzle such as megasonic power, and the gap between puddle nozzle and cleaned surface were investigated
for opaque SRAFs sizes of 107 nm, 93 nm, 81nm, 71 nm, 63 nm, and 56 nm. Damage-free and high efficiency on
particle removal cleaning for SRAFs size down to 71 nm for 38 nm technology node (MPU/ASIC 1/2 pitch, as outlined in
ITRS 2010) has been demonstrated on advanced photomask with MoSi layer in this paper. Furthermore, conducting
atomic force microscopy (CAFM) was employed to investigate the nanoscale surface electrical properties of chrome
binary blanks cleaned by 1 MHz puddle megasonic nozzle. The results show that highly conducting regions on
chromium oxide surfaces can be considered as "cavitation-rich and/or cavitation energy-strong" regions. And their sizes
range from 15 to 100 nm, which are comparable to the sizes of SRAFs damage. Finally, in the future, CAFM may be a
useful tool to inspect intrinsic defects on advanced photomasks at nanoscale, such as EUV blanks.
ALTA4700 DUV laser pattern generator employs chemical amplified resist to get better resolution. The capability of
ALTA4700 for 130nm technology node mask production is obviously. Further improvement on ALTA4700 was
performed to meet the state-of-the-art mask requirement. System optimization eliminates unusual critical dimension (CD)
points and then reduces the range of uniformity. Appropriate post-exposure baking (PEB) temperature gets larger mask
printing window and better CD linearity. ALTA4700 incorporate NTAR7 blank with particular dry etch recipe, the mask
CD uniformity reduced from 25 to 15nm (range). Good Cr layer profile also obtains.
Evaluation of the writing strategy effects with one and two pass exposed by EBM-4000 variable-shaped e-beam lithography tool is a new class of mask making especially for OPC technology. The EBM-4000 writing system features a variable shaped beam, 50 KeV accelerating voltage, a continuous stage, and incorporates some technologies. Obviously, many examples exist of systems which add parallelism to the exposure process by using multiple pass. The standard writing strategy of EBM-4000 writing system is four pass. We evaluated and confirmed the two pass exposed by EBM-4000 writing system for 90 to 130 nm node successfully. The results of the two pass improved throughput and had excellent performances.
In the present paper, the one and two pass exposed by EBM-4000 writing system has been investigated. The objective of the present work is to direct the performances for several design of OPC verification like serifs and jogs. We will provide the actual measurement data and images obtained on CD-SEM for the OPC pattern exposed with one and two pass. In this paper, the characterization data will also present the applicable results such as resolution, position accuracy, global and local CD uniformity, CD linearity, and roughness. We have evaluated and confirmed the one and two pass writing strategies for the EBM-4000 writing system. The writing strategies are especially desirable for unique properties due to the best conditions of the CAR process.
Analyses of the effects of positive and negative chemically amplified resist (CAR) exposed by
Leica ZBA31H+ 20 KeV shaped e-beam lithography tool are investigated using CD-SEM. The
characterization data will present improved resolution, global CD uniformity and CD linearity. During last few years, several resists were used for masks making. The e-beam resists as ZEP and
PBS resists were used on Leica low acceleration voltage e-beam system previous years. In the
present investigation, the CA resist exposed by Leica ZBA31H+ 20 KeV writing system has been
investigated. The objective of the present work is directed toward that the CAR process improves
higher throughput than ZEP resist and promotes better performances than both ZEP and PBS
For the high exposed loading, to minimize writing time and fogging effect, and to control mean CD
and improve global CD uniformity, the negative CA resist performs better than positive CA resist.
TMC provides the actual measurement data obtained on CD-SEM for negative CA resist exposed
by Leica 20 KeV writing system. In this paper, we will also provide the applicable profile results
obtained on CD-SEM to confirm the feasibility for CAR mask be exposed by Leica 20 KeV