The news comes as Globalfoundries, Samsung and TSMC compete to upgrade their EUV system to a highly available 250W light source for next year's 7nm production. Nowadays, these random defects have emerged. Display, for the increasing cost and complexity of semiconductor manufacturing, there is no magic bullet to solve the problem.
Greg McIntyre, a graphic expert at the Imec Research Institute in Belgium, said at the SPIE Advanced Lithography conference held in California, USA that the latest EUV scanner can print the 20nm planned by the foundry for 7nm. And the larger size of the key specifications. However, their ability to make fine lines and holes is not clear.
Optimists like McIntyre believe that a series of solutions will quickly appear for this so-called 'random effect'. However, some skeptics believe that such a result is only one more questionable EUV system. Rationale – Is an expensive and long-delayed EUV system really a mainstream tool for chip makers?
Yan Borodovsky, a former Intel lithography technologist, expected that industry engineers should be able to use the EUV stepper for 2-3 exposures to create 5nm or even 3nm components. But he also pointed out in the keynote speech at the event. As chip defects continue to rise, engineers will eventually be forced to adopt new fault-tolerant processor architectures such as neural networks.
The most recent defect suddenly appeared at a critical size of around 15nm, which is the technological node required to manufacture a 5nm chip for industrial processes in the 2020s. EUV manufacturer ASML mentioned in last year's event that the company is preparing to print more. Fine-grained next-generation EUV systems, but these systems won’t be available until 2024.
Random defects come in many forms. Some are holes that cause imperfections; others are linear cracks, or short circuits between two wires and two holes. Because the size of these flaws is too small, researchers sometimes have to spend a few. It takes days to find it.
McIntyre describes the challenges that can be encountered in the discovery and elimination of errors. For example, some researchers have proposed a standard method for measuring the roughness of a line, which is one of the keys to understanding defects.
Another problem is that it is not yet clear what happens to the photoresist material when it hits the EUV light source. McIntyre pointed out, 'We don't know yet how many electrons will be produced and what chemical substances will be created... We also have to do with physics. Not completely understood, so more experiments are underway. 'He pointed out that researchers have tested up to 350 combinations of photoresists and process steps.
Good yield at 7nm/5nm
'The manufacturing sector will be hit hard by the drop in yield... If I'm responsible for it, then I'm going to say it's time to retire,' said a retired lithography technologist at a seminar on the 5nm defect. .
Technologists from Globalfoundries gave a more optimistic but relatively sensible view in another keynote speech. George Gomba, vice president of research at Globalfoundries, said in reviewing his journey to EUV for nearly 30 years: 'This is a difficult task. , And then there's more work to do.'
Today's NXE 3400 system 'does not meet some of the development blueprints that we expected, so there is still some uncertainty at '7nm'. If we do not increase productivity and availability, we may find it difficult to maximize the value of EUV.'
Gomba pointed out that random defects at 5nm include subtle 3D fractures and tears, such as gaps in lines. He also called for more work on so-called actinic systems, so that lithography technicians can use masks to protect the film. Detect EUV masks before covering.
'In order to fully utilize EUV, we will need a photochemical detection system. Although it is still under development, it can assist e-beam mask detection systems that are currently available.'
Borodovsky said in an interview that another factor that may cause 5nm defects is the lack of uniformity of existing EUV photoresist materials. In addition, he also expressed support for direct electron beam writing because the complex phase shift mask used by EUV will eventually Expanded to 8 times the price of current immersion masks.
Multibeam, a company founded by Lam Research founder David Lam, recently obtained US$35 million in government funding for its electron beam technology. He hopes to create a commercial system that can be applied to the market in two and a half years, but it is suitable for a large number of The production version also takes longer.
Borodovsky said that by 2024, defects may become so common that traditional processors will not be able to be manufactured with advanced processes. Experimental chips using memory arrays and built-in embedded computing elements may have higher fault tolerance, such as IBM's True North chip, and HP Labs' achievements with memristors.
