Enabling Advanced Devices With Atomic Layer Processes


Atomic layer deposition (ALD) used to be considered too slow to be of practical use in semiconductor manufacturing, but it has emerged as a critical tool for both transistor and interconnect fabrication at the most advanced nodes. ALD can be speeded up somewhat, but the real shift is the rising value of precise composition and thickness control at the most advanced nodes, which makes the ext... » read more

Lithography Options For Next-Gen Devices


Chipmakers are ramping up extreme ultraviolet (EUV) lithography for advanced logic at 7nm and/or 5nm, but EUV isn’t the only lithographic option on the table. For some time, the industry has been working on an assortment of other next-generation lithography technologies, including a new version of EUV. Each technology is different and aimed at different applications. Some are here today, w... » read more

Single Vs. Multi-Patterning EUV


Extreme ultraviolet (EUV) lithography finally is moving into production, but foundry customers now must decide whether to implement their designs using EUV-based single patterning at 7nm, or whether to wait and instead deploy EUV multiple patterning at 5nm. Each patterning scheme has unique challenges, making that decision more difficult than it might appear. Targeted for 7nm, single pattern... » read more

What Drives SADP BEOL Variability?


Until EUV lithography becomes a reality, multiple patterning technologies such as triple litho-etch (LELELE), self-aligned double patterning (SADP), and self-aligned quadruple patterning (SAQP) are being used to meet the stringent patterning demands of advanced back-end-of-line (BEOL) technologies. For the 7nm technology node, patterning requirements include a metal pitch of 40nm or less. This ... » read more

Timing Closure Issues Resurface


Timing closure has resurfaced as a major challenge at 10nm and 7nm due to more features and power modes, increased process variation and other manufacturing-related issues. While timing-related problems are roughly correlated to rising complexity in semiconductors, they tend to generate problems in waves—about once per decade. In SoCs, timing closure problems have spawned entire methodolog... » read more

Fill/Cut Self-Aligned Double-Patterning


By David Abercrombie, Rehab Ali, Ahmed Hamed-Fatehy, and Shetha Nolke Self-aligned double patterning (SADP) is an alternative double-patterning process to the traditional litho-etch-litho-etch (LELE) approach used in most advanced production nodes. The main difference between the two approaches is that in LELE, the layout is divided between two masks, and the second mask is aligned with resp... » read more

1xnm DRAM Challenges


At a recent event, Samsung presented a paper that described how the company plans to extend today’s planar DRAMs down to 20nm and beyond. This is an amazing feat. Until very recently, most engineers believed DRAMs would stop scaling at 20nm or so. Instead, Samsung is ramping up the world’s most advanced DRAMs—a line of 20nm parts—with plans to go even further. Micron and SK Hynix soo... » read more

Flash Dance For Inspection And Metrology


Chipmakers are moving from planar technology to an assortment of 3D-like architectures, such as 3D NAND and finFETs For these devices, chipmakers face a multitude of challenges in the fab. But one surprising and oft-forgotten technology is emerging as perhaps the biggest challenge in both logic and memory—process control. Process control includes metrology and wafer inspection. Metrolo... » read more

Self-Aligned Double Patterning—Part Deux


In my last article, I introduced you to the basic Self-Aligned Double-Patterning (SADP) process that is one of the potential candidate techniques for processing metal layers at 10nm and below, but let’s have a quick recap. SADP uses a deposition and etch step process to create spacers surrounding a patterned shape (Figure 1). As you can see, there are two masking steps—the first mask is cal... » read more

Self-Aligned Double Patterning, Part One


I’m sure most of you have seen a Rorschach test ink blot (Figure 1). Psychiatrists ask the subjects to tell them what they “see” in the ink blot. The answers are used to characterize the respondent’s personality and emotional functioning. I am never sure if I would feel more uncertain being the psychiatrist asking the question, or the subject trying to decide what to say, given there ar... » read more

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