Assessing EUV Wafer Output: 2019-2022

Assessing EUV Wafer Output: 2019-2022
by Fred Chen on 06-26-2023 at 6:00 am

Assessing EUV Wafer Output 2019 2022

At the 2023 SPIE Advanced Lithography and Patterning conference, ASML presented an update on its EUV lithography systems in the field [1]. The EUV wafer exposure output was presented and is shown below in table form:

From this information, we can attempt to extract and assess the EUV wafer output per quarter. First, since there … Read More


Application-Specific Lithography: 28 nm Pitch Two-Dimensional Routing

Application-Specific Lithography: 28 nm Pitch Two-Dimensional Routing
by Fred Chen on 06-19-2023 at 6:00 am

Brightfield (red) and darkfield (purple) sidelobes in 84 nm

Current 1a-DRAM and 5/4nm foundry nodes have minimum pitches in the 28 nm pitch range. The actual 28 nm pitch patterns are one-dimensional active area fins (for both DRAM and foundry) as well as one-dimensional lower metal lines (in the case of foundry). One can imagine that, for a two-dimensional routing pattern, both horizontal… Read More


A Primer on EUV Lithography

A Primer on EUV Lithography
by Fred Chen on 06-02-2023 at 6:00 am

Litho historical trend Fig 1

Extreme ultraviolet (EUV) lithography systems are the most advanced lithography systems in use today. This article is a basic primer on this important yet complex technology.

The Goal: A Smaller Wavelength

The introduction of 13.5 nm wavelength continues a trend the semiconductor industry had been following a wavelength reduction… Read More


Curvilinear Mask Patterning for Maximizing Lithography Capability

Curvilinear Mask Patterning for Maximizing Lithography Capability
by Fred Chen on 05-09-2023 at 10:00 am

Curvilinear 1

Masks have always been an essential part of the lithography process in the semiconductor industry. With the smallest printed features already being subwavelength for both DUV and EUV cases at the bleeding edge, mask patterns play a more crucial role than ever. Moreover, in the case of EUV lithography, throughput is a concern, … Read More


Reality Checks for High-NA EUV for 1.x nm Nodes

Reality Checks for High-NA EUV for 1.x nm Nodes
by Fred Chen on 04-26-2023 at 6:00 am

Reality Checks for High NA EUV for 1.x nm Nodes

The “1.xnm” node on most roadmaps to indicate a 16-18 nm metal line pitch [1]. The center-to-center spacing may be expected to be as low as 22-26 nm (sqrt(2) times line pitch). The EXE series of EUV (13.5 nm wavelength) lithography systems from ASML feature a 0.55 “High” NA (numerical aperture), targeted… Read More


Can Attenuated Phase-Shift Masks Work For EUV?

Can Attenuated Phase-Shift Masks Work For EUV?
by Fred Chen on 04-18-2023 at 6:00 am

1679926948898

Normalized image log-slope (NILS) is probably the single most essential metric for describing lithographic image quality. It is defined as the slope of the log of intensity, multiplied by the linewidth [1], NILS = d(log I)/dx * w = w/I dI/dx.  Essentially, it gives the % change in width for a given % change in dose. This is particularly… Read More


Lithography Resolution Limits: The Point Spread Function

Lithography Resolution Limits: The Point Spread Function
by Fred Chen on 03-21-2023 at 6:00 am

Lithography Resolution Limits The Point Spread Function

The point spread function is the basic metric defining the resolution of an optical system [1]. A focused spot will have a diameter defined by the Airy disk [2], which is itself a part of the diffraction pattern, based on a Bessel function of the 1st kind and 1st order J1(x), with x being a normalized coordinate defined by pi*radius/(0.5… Read More


Resolution vs. Die Size Tradeoff Due to EUV Pupil Rotation

Resolution vs. Die Size Tradeoff Due to EUV Pupil Rotation
by Fred Chen on 03-02-2023 at 10:00 am

Resolution vs. Die Size Tradeoff Due to EUV Pupil Rotation

The many idiosyncrasies of EUV lithography affect the resolution that can actually be realized. One which still does not get as much attention as it should is the cross-slit pupil rotation [1-3]. This is a fundamental consequence of using rotational symmetry in ring-field optical systems to control aberrations in reflective… Read More


Multiple Monopole Exposures: The Correct Way to Tame Aberrations in EUV Lithography?

Multiple Monopole Exposures: The Correct Way to Tame Aberrations in EUV Lithography?
by Fred Chen on 02-01-2023 at 6:00 am

Multiple Monopole Exposures 1

For a leading-edge lithography technology, EUV (extreme ultraviolet) lithography is still plagued by some fundamental issues. While stochastically occurring defects probably have been the most often discussed, other issues, such as image shifts and fading [1-5], are an intrinsic part of using reflective EUV optics. However,… Read More


Application-Specific Lithography: Sub-0.0013 um2 DRAM Storage Node Patterning

Application-Specific Lithography: Sub-0.0013 um2 DRAM Storage Node Patterning
by Fred Chen on 01-17-2023 at 10:00 am

Application Specific Lithography 1

The pursuit of ever smaller DRAM cell sizes is still active and ongoing. DRAM cell size is projected to approach 0.0013 um2 for the D12 node. Patterning challenges are significant whether considering the use of DUV or EUV lithography. In particular, ASML reported that when center-to-center values reached 40 nm, single patterning… Read More