Cost-effective shrink of semi-critical layers using the TWINSCAN XT:1000H NA 0.93 KrF scanner

Production feasibility under groundrules smaller than 0.09 um while maintain the cost advantages in KrF exposure tools systems becomes more and more important to all companies including 300mm/200mm FABs. The k1 factor for sub 0.09um with current popular KrF exposure tools will be comprable to 0.028 um at 1.3 NA with 193 nm immersion tools. For line/space patterns, some good results had been achieved. But for contact hole patterns, the patterning is much more challenging. It is the biggest obstacle to transfer all layers patterning from ArF to KrF tools on sub-90nm technology node. In order to improve cotanct holes resoltuion and process window, lots of methods had been proposed in advanced technology. But their manufacturing costs are not satisfied when they are used in 90nm nodes with pure KrF process. In this paper, we will discuss the contact hole patterning with focus tilting technology on 0.82NA KrF scanners. The process window, OPC performance and its issues are discussed. Combine with the line/space pattern results, all layers design rule with KrF process had been pushed to the same level of gerneric ArF process at 90nm nodes.

Section: Introductionsupporting

confidence: 66%

90nm Contact Hole Study with KrF Process

Wang¹,

Guo²,

Xu³

2014

“…Meanwhile, there are some new requirements for cost saving which have become more and more popular and the classical low k1 methods are not effective [8][9][10][11][12]. Sub 90nm design rule products mass produced with pure KrF process is an example.…”

Section: Introductionmentioning

confidence: 99%

DFM Study in Low k1 Lithography Process

Wang¹,

Guo²,

Liu³

et al. 2012

For low k1 lithography process, some minor facotrs' impacts are strongly enhanced such as MEEF, lens distortion, wafer topography, pattern density and so on. How to minimize those impacts becomes more and more important. Unfortunately those impacts are not controlled by lithography process itself and caused by other modules such as layout design, integration schemes, mask making, film deposition, CMP and so on. A method to reduce those impacts is quietly needed. DFM (Design for Manufacturability) is a popular and effective approach to get more robust process by reducing pattern loading effect. In this paper, we will show our study on wafer local topography in low k1 lithography process. Products with sub-90nm design rules and different device structures are processed by pure KrF process. The maximum 0.82NA KrF scanner tools are used. The k1 factor is low enough to enhance the impacts. By using DFM solutions, we had resolved these issues and the process window are obviously improved.

“…The ASP (Average Sales Price) for industry popular 0.09 um and sub 0.09 um technology product based on ArF exposure systems becomes more close to low end products and cost down is much important. As a result, the motivation to transfer 0.09um and sub 0.09um products to KrF exposure systems is increased [1][2][3][4][5].…”

Section: Introductionmentioning

confidence: 99%

“…The most effective solution is increasing the NA to achieve larger k1 factor. Some good results have been demonstrated with new high NA KrF exposure systems [4][5]. But it is not to be a cost effective solution for current companies.…”

Section: Introductionmentioning

confidence: 99%

248nm Process Is Capable for sub 0.09 um Groundrules

Wang¹,

Guo

Tong

et al. 2011

While the mainstream wafer production is at 0.065 and 0.045 um with 300 mm diameter wafers with ArF exposure tools systems, an idea to explore production feasibility under groundrules smaller than 0.09 um while maintain the cost advantages in KrF exposure tools systems becomes more and more popular and important to all companies including 300mm/200mm FAB. But the k1 factor for sub 0.09um with current popular KrF exposure tools will be about 0.31, which has the same level of complexity in optical proximity correction compared to 0.045 um at 0.93 NA with 193 nm exposure tools. Several RET (Resolution Enhancement Technology) techniques have been proposed for low k1 case and some good results have been achieved. However, each RET techniques has their own merits and demerits. It is still attractive to find out a solution with current KrF exposure tools, popular illumination settings and cost effective masks. In this paper, we will introduce our study for sub 0.09 um design rule with maximum 0.82NA KrF scanner tools. No special RET techniques are used and acceptable DOF, EL, MEEF, LWR and CD proximity are achieved. A novel photoresist optimization solution is both discussed.