Resist Parameter Extraction from Line-and-Space Patterns of Chemically Amplified Resist for Extreme Ultraviolet Lithography

Abstract

The development of extreme ultraviolet (EUV) lithography has progressed owing to worldwide effort. As the development status of EUV lithography approaches the requirements for the high-volume production of semiconductor devices with a minimum line width of 22 nm, the extraction of resist parameters becomes increasingly important from the viewpoints of the accurate evaluation of resist materials for resist screening and the accurate process simulation for process and mask designs. In this study, we demonstrated that resist parameters (namely, quencher concentration, acid diffusion constant, proportionality constant of line edge roughness, and dissolution point) can be extracted from the scanning electron microscopy (SEM) images of patterned resists without the knowledge on the details of resist contents using two types of latest EUV resist. #

Requirement for Suppression of Line Width Roughness in Fabrication of Line-and-Space Patterns with 7 nm Quarter-Pitch Using Electron Beam Lithography with Chemically Amplified Resist Process

“…D acid was assumed to be 1 nm , for simplicity. Note that the acid diffusion constants of current high-performance resists have been evaluated to be 2−10 nm 2 s -1 [22][23][24][25][26]. D q was assumed to be 0 nm .…”

Relationship between Absorption Coefficient and Line Edge Roughness of Chemically Amplified Resists Used for Extreme Ultraviolet Lithography

“…[38] The effective reaction radii for neutralization and deprotection were set to typical values of 0.5 and 0.1 nm, respectively. [23][24][25][26] LER was evaluated using [23] dx dm…”

“…The proportionality constant f LER of state-of-the-art chemically amplified resists has been estimated to be 0.17-0.31. [23][24][25][26] Other details of the reaction mechanisms and parameters have been described in ref. 39.…”

“…The physical parameters that determine resist pattern formation have been investigated for the latest high-performance chemically amplified resists using the small-field exposure tool (SFET) of Selete. [23][24][25][26][27] LER of the high-absorption resists was estimated by applying these experimental parameters to a simulation based on the sensitization and reaction mechanisms of chemically amplified EUV resists. The dependence of the relationship between LER and absorption coefficient on pattern size, acid generator concentration, and exposure dose is discussed.…”

A Comprehensive Review of EUV Resist Materials and Processing at Selete

“…At present, EUV resist sensitivity and resolution limits continue to be improved but line width roughness (LWR) still remains a difficult issue [2] . To provide possible solutions, there is a trend in individual and collaborative efforts between research consortiums, universities, and resist material developers on the investigation of new EUV resist platform and material designs [3][4][5][6][7][8][9] . This is also true for the conceptualization and application of alternative resist processes which have shown significant potential as pattern sizes become smaller [10][11][12][13] .…”