Background: To increase the resolution and depth of focus (DOF) of flat panel display (FPD) exposure systems, off-axis illumination (OAI) conditions are used extensively. OAI using narrowband wavelength illumination has been studied sufficiently. In contrast, new techniques that consider broadband wavelength illumination are needed because the effects of OAI differ between broadband and narrowband

We review the history in connection with the resolution formula of microlithography and argue that it was Abbe rather than Rayleigh who definitively stated the 0.5λNA resolution limit for the minimum pitch first, using an approach more relevant to projection imaging, and hence, this expression should be more appropriately referred to as the Abbe formula for the resolution of a projection imaging system

In this editorial, the co-editors-in-chief outline the journal’s new direction.

Background: Conventional scanning electron microscopy (SEM) that is used for 2D top-view metrology, a classical line edge roughness (LER) measurement technique, is incapable of measuring 3D structures of a nanoscale line pattern. For LER measurements, SEM measurement generates a single line-edge profile for the 3D sidewall roughness, although the line-edge profile differs at each height in the 3D sidewall

Background: Although the wet cleaning process has been widely used in semiconductor device manufacturing due to its convenience, it faces theoretical limits. That is, when the size of the objected particle is smaller than 100 nm, it is buried in the stagnant layer where there is substantially no fluid flow. Aim: Only small particles below the stagnant layer (<100 nm) is removed without any damage to

Next-generation extreme ultraviolet (EUV) systems with numerical apertures of 0.55 have the potential to provide sub-8-nm half-pitch resolution. The increased importance of stochastic effects at smaller feature sizes places further demands on scanner and mask to provide high contrast images. We use rigorous mask diffraction and imaging simulation to understand the impact of the EUV mask absorber and

With the introduction of the NXE:3400B scanner, ASML has brought extreme ultraviolet lithography (EUV) to high-volume manufacturing (HVM). The high-EUV power of >200 W being realized with this system satisfies the throughput requirements of HVM, but also requires reconsideration of the imaging aspects of spectral purity, both from the details of the EUV emission spectrum and from the deep-ultraviolet

Background: Line-edge roughness (LER) is often measured from top-down critical dimension scanning electron microscope (CD-SEM) images. The true three-dimensional roughness profile of the sidewall is typically ignored in such analyses. Aim: We study the response of a CD-SEM to sidewall roughness (SWR) by simulation. Approach: We generate random rough lines and spaces, where the SWR is modeled by a known

JM3 Co-Editor-in-Chief Harry Levinson introduces new guidelines regarding materials for lithography.

Source mask and polarization optimization (SMPO) is a promising extension of the widely used resolution enhancement technology, source mask optimization (SMO), to further enhance chip manufacturability beyond 28-nm node. Our work is aimed to develop an efficient gradient-based SMPO method by employing the hybrid Hopkins–Abbe imaging model to fulfill the goal. In addition to source and mask variables

In extreme ultraviolet (EUV) lithography, chemistry is driven by secondary electrons. A deeper understanding of these processes is needed. However, electron-driven processes are inherently difficult to experimentally characterize for EUV materials, impeding targeted material engineering. A computational framework is needed to provide information for rational material engineering and identification

Background: Molecular logic circuits have great potential applications. DNA logic circuit is an important research direction of DNA computing in nanotechnology. DNA self-assembly has become a powerful tool for building nanoscale structures. The combination of different self-assembly methods is an interesting topic. Aim: Two different self-assembly methods are combined to realize large-scale logic circuit

Background: With aggressive scaling of single-expose (SE) extreme ultraviolet (EUV) lithography to the sub-7-nm node, stochastic variations play a prominent role in defining the lithographic process window (PW). Fluctuations in photon shot noise, absorption, and subsequent chemical reactions can lead to stochastic failure, directly impacting electrical yield. Aim: Fundamental characterization of the

We demonstrate a hybrid "package-less" polydimethylsiloxane (PDMS)-complementary-metal-oxide-semiconductor (CMOS)-FR4 system for contact imaging. The system embeds the CMOS image sensor directly in a PDMS layer instead of the standard chip package to support microfluidic structures much larger and more complex than those in prior art. The CMOS/PDMS layer is self-aligned to form a continuous, flat surface

Methods exist for the creation of antireflective thin film layers; however, many of these methods depend on the use of high temperatures, harsh chemical etches, or are made with difficult pattern materials, rendering them unusable for many applications. In addition, most methods of light blocking are specifically designed to increase light coupling and absorption in the substrate, making them incompatible

The decreasing size of semiconductor features and the increasing structural complexity of advanced devices have placed continuously greater demands on manufacturing metrology, arising both from the measurement challenges of smaller feature sizes and the growing requirement to characterize structures in more than just a single critical dimension. For scanning electron microscopy, this has resulted in

We compare the speed and effectiveness of two genetic optimization algorithms to the results of statistical sampling via a Markov chain Monte Carlo algorithm to find which is the most robust method for determining real space structure in periodic gratings measured using critical dimension small angle X-ray scattering. Both a covariance matrix adaptation evolutionary strategy and differential evolution

Sidewall sensing in critical dimension atomic force microscopes (CD-AFMs) usually involves continuous lateral dithering of the tip or the use of a control algorithm and fast response piezo actuator to position the tip in a manner that resembles touch-triggering of coordinate measuring machine (CMM) probes. All methods of tip position control, however, induce an effective tip width that may deviate