Resist freezing process for double exposure lithography

Abstract

In this study, we have developed a thermal freezing process to prevent intermixing between 1 st patterned positive resist and 2 nd positive resist. Based on solvent solubility switch characteristic of polymer after higher temperature bake, a prototype of polymer consisting of methyladmantane mathacrylate, norbornanecarbo lactone mathacrylate and hydroxyl admantane mathacrylate was selected for resist-on-resist double exposure experiment to prevent the intermixing between layers. Photo sensitivity shifting of this prototype resist after post develop bake further facilitates the design by preventing 1st layer resist distortion from 2nd exposure. Lastly, through composition and formulation optimization, 35nm L/S patterns were successfully demonstrated by using a 1.2NA stepper.

Temperature- and Cost-Aware Design of 3D Multiprocessor Architectures

“…We apply the alternate color assignment to the timing-critical paths and uniform color assignment to the clock paths, but do not apply DPL-Corr that may introduce other timing uncertainty from placement perturbation and ECO-routing. 3 We compare the CSCP and T NS values of the initially colored design (initial colored.def) with those of an optimally colored design (opt colored.def). Table 4 shows CSCP and T NS reduction from the alternate color assignment on different top-k critical paths of AES70.…”

“…Double exposure [1], double patterning [2] [7] and sacrificial spacer double patterning [11] are three major types of double patterning in the International Technology Roadmap for Semiconductors (ITRS) [18], and with variants to enhance printability and reduce variability [3] [12].…”

ORION 2.0: A fast and accurate NoC power and area model for early-stage design space exploration

“…As there is more than one mask per layer for which double patterning is applied 2 , mask misalignment becomes a problem. For SDP, instead of mask misalignment, spacer thickness determines an important part of the overlay error.…”

Cure-induced photoresist distortions in double patterning

“…Without stabilization, the first resist pattern will swell or dissolve on application of the second resist film, or undergo additional exposure and development during the patterning of the second resist. Numerous chemical, 3,6,[9][10][11][12][13] photochemical, [1][2][3][4]14 thermal, 8 and ion-beam 5,7,15 stabilization methods have recently been described.…”

“…1͒. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] Stabilization of the first photoresist pattern before processing of the second resist pattern is necessary in double imaging. Without stabilization, the first resist pattern will swell or dissolve on application of the second resist film, or undergo additional exposure and development during the patterning of the second resist.…”