High-NA EUV lithography is the anticipated new lithography technology to be introduced for the 2nm node. Essentially, it replaces the 0.33 numerical aperture of current EUV systems with a higher 0.55 numerical aperture (NA). This allows the projection of smaller spot sizes and smaller pitches, roughly 60% smaller compared … Read More
Application-Specific Lithography: Via Separation for 5nm and Beyond
With metal interconnect pitches shrinking in advanced technology nodes, the center-to-center (C2C) separations between vias are also expected to shrink. For a 5/4nm node minimum metal pitch of 28 nm, we should expect vias separated by 40 nm (Figure 1a). Projecting to 3nm, a metal pitch of 24 nm should lead us to expect vias separated… Read More
ASML Update SEMICON West 2023
At SEMICON West I had a chance to catch up with Mike Lercel of ASML. In this article I am going to combine ASML presentation material from the SPIE Advanced Lithography Conference, Mike’s SEMICON presentation, my discussions with Mike at SEMICON and a few items from ASML’s recent earnings call.
DUV
ASML continues to improve DUV systems.… Read More
NILS Enhancement with Higher Transmission Phase-Shift Masks
In the assessment of wafer lithography processes, normalized image log-slope (NILS) gives the % change in width for a given % change in dose [1,2]. A nominal NILS value of 2 indicates 10% change in linewidth for 10% change in dose; the % change in linewidth is inversely proportional to the NILS. In a previous article [2], it was shown… Read More
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
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
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
SPIE 2023 – imec Preparing for High-NA EUV
The SPIE Advanced Lithography Conference was held in February. I recently had the opportunity to interview Steven Scheer, vice president of advanced patterning process and materials at imec and review selected papers that imec presented.
I asked Steve what the overarching message was at SPIE this year, he said readiness for … Read More
Curvilinear Mask Patterning for Maximizing Lithography Capability
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
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
CHIPS Act dies because employees are fired – NIST CHIPS people are probationary