Scanner introduction into the fab production environment is a challenging task. An efficient evaluation of scanner
performance matrices during factory acceptance test (FAT) and later on during site acceptance test (SAT) is crucial for
minimizing the cycle time for pre and post production-start activities. If done effectively, the matrices of base line
performance established during the SAT are used as a reference for scanner performance and fleet matching monitoring
and maintenance in the fab environment.
Key elements which can influence the cycle time of the SAT, FAT and maintenance cycles are the imaging, process and
mask characterizations involved with those cycles.
Discrete mask measurement techniques are currently in use to create across-mask CDU maps. By subtracting these maps
from their final wafer measurement CDU map counterparts, it is possible to assess the real scanner induced printed errors
within certain limitations. The current discrete measurement methods are time consuming and some techniques also
overlook mask based effects other than line width variations, such as transmission and phase variations, all of which
influence the final printed CD variability.
Applied Materials Aera2TM mask inspection tool with IntenCDTM technology can scan the mask at high speed, offer full mask coverage and accurate assessment of all masks induced source of errors simultaneously, making it beneficial for
scanner qualifications and performance monitoring.
In this paper we report on a study that was done to improve a scanner introduction and qualification process using the
IntenCD application to map the mask induced CD non uniformity. We will present the results of six scanners in production and discuss the benefits of the new method.
The economy of wafer fabs is changing faster for 3x geometry requirements and below. Mask set and exposure tool
costs are almost certain to increase the overall cost per die requiring manufacturers to develop productivity and yield
improvements to defray the lithography cell economic burden. Lithography cell cost effectiveness can be
significantly improved by increasing mask availability while reducing the amount of mask sets needed during a
product life cycle. Further efficiency can be gained from reducing send-ahead wafers and qualification cycle time,
and elimination of inefficient metrology. Yield is the overriding die cost modulator and is significantly more
sensitive to lithography as a result of masking steps required to fabricate the integrated circuit. Thus, for productivity
to increase with minimal yield risk, the sample space of reticle induced source of variations should be large, with
shortest measurement acquisition time possible.
This paper presents the latest introduction of mask aerial imaging technology for the fab, Aera2TM for Lithography
with IntenCTM, as an enabler for efficient lithography manufacturing. IntenCD is a high throughput, high density
mask-based critical dimension (CD) mapping technology, with the potential for increasing productivity and yield in
a wafer production environment. Connecting IntenCD to a feed forward advance process control (APC) reduces
significantly the amount of traditional CD metrology required for robust wafer CD uniformity (CDU) correction and
increases wafer CD uniformity. This in turn improves the lithography process window and yield and contributes to
cost reduction and cycle time reduction of new reticles qualification.
Advanced mask technology has introduced a new challenge. Exposure to 193nm wavelength stimulates haze growth
on the mask and imposes a regular cleaning schedule. Cleaning eventually causes mask degradation. Haze growth
impacts mask CD uniformity and induce global transmission fingerprint variations. Furthermore, aggressive
cleaning may damage the delicate sub-resolution assist features. IntenCD based CDU fingerprint correction can
optimize the regular mask cleaning schedule, extending clean intervals therefore extending the overall mask life
span. This mask availability enhancement alone reduces the amount of mask sets required during the product life
cycle and potentially leads to significant savings to the fab.
This mask availability enhancement alone reduces the amount of mask sets required during the product life cycle
and leads to significant savings to the fab.
In this paper we present three case studies from a wafer production fab and a mask shop. The data presented
demonstrates clear productivity and yield enhancements. The data presented is the outcome of a range of new
applications which became possible by integrating the recently introduced Applied Materials Aera2TM for
Lithography aerial imaging inspection tool with the litho cluster.
We present a brief overview of a promising switching technology based on Silica on Silicon thermo-optic integrated circuits. This is basically a 2D solid-state optical device capable of non-blocking switching operation. Except of its excellent performance (insertion loss<5dB, switching time<2ms...), the switch enables additional important build-in functionalities. It enables single-to- single channel switching and single-to-multiple channel multicasting/broadcasting. In addition, it has the capability of channel weighting and variable output power control (attenuation), for instance, to equalize signal levels and compensate for unbalanced different optical input powers, or to equalize unbalanced EDFA gain curve. We examine the market segments appropriate for the switch size and technology, followed by a discussion of the basic features of the technology. The discussion is focused on important requirements from the switch and the technology (e.g., insertion loss, power consumption, channel isolation, extinction ratio, switching time, and heat dissipation). The mechanical design is also considered. It must take into account integration of optical fiber, optical planar wafer, analog electronics and digital microprocessor controls, embedded software, and heating power dissipation. The Lynx Photon.8x8 switch is compared to competing technologies, in terms of typical market performance requirements.