A radiation sensitive resin composition comprising (A) a fluorine-containing copolymer of hexafluoropropylene, at least one compound selected from the group consisting of unsaturated carboxylic acids and unsaturated carboxylic anhydrides, and an unsaturated compound (B) an acid generating compound which generates an acid upon exposure to radiation; (C) a cross-linkable compound; and (D) an organic solvent. The composition suitable is useful for a negative resist for forming a mask for the production of a circuit such as a semiconductor integrated circuit or a thin film transistor circuit for liquid crystal displays as well as a material for forming a permanent film such as an interlaminar insulating film or a color filter protective film.

Radiation-sensitive resin composition

A lithographic apparatus configured to project a patterned beam of radiation onto a target portion of a substrate is disclosed. The apparatus includes a first radiation dose detector and a second radiation dose detector, each detector comprising a secondary electron emission surface configured to receive a radiation flux and to emit secondary electrons due to the receipt of the radiation flux, the first radiation dose detector located upstream with respect to the second radiation dose detector viewed with respect to a direction of radiation transmission, and a meter, connected to each detector, to detect a current or voltage resulting from the secondary electron emission from the respective electron emission surface.

Lithographic apparatus, and device manufacturing method

A method and apparatus for creating a phase shifting mask and a structure mask for shrinking integrated circuit designs. One embodiment of the invention includes using a two mask process. The first mask is a phase shift mask and the second mask is a single phase structure mask. The phase shift mask primarily defines regions requiring phase shifting. The single phase structure mask primarily defines regions not requiring phase shifting. The single phase structure mask also prevents the erasure of the phase shifting regions and prevents the creation of undesirable artifact regions that would otherwise be created by the phase shift mask. Both masks are derived from a set of masks used in a larger minimum dimension process technology.

Phase shifting circuit manufacture method and apparatus

Historically, in the mass production of semiconductor devices, exposure tools have been repeatedly replaced with those with a shorter wavelength to meet the resolution requirements projected in the International Technology Roadmap for Semiconductors issued by the Semiconductor Industry Association. After ArF immersion lithography, extreme ultraviolet (EUV; 92.5 eV) radiation is expected to be used as an exposure tool for the mass production at or below the 22 nm technology node. If realized, 92.5 eV EUV will be the first ionizing radiation used for the mass production of semiconductor devices. In EUV lithography, chemically amplified resists, which have been the standard resists for mass production since the use of KrF lithography, will be used to meet the sensitivity requirement. Above the ionization energy of resist materials, the fundamental science of imaging, however, changes from photochemistry to radiation chemistry. In this paper, we review the radiation chemistry of materials related to chemically amplified resists. The imaging mechanisms from energy deposition to proton migration in resist materials are discussed.

https://iopscience.iop.org/article/10.1143/JJAP.49.030001/pdf

Radiation Chemistry in Chemically Amplified Resists

A direct, accurate and convenient procedure for calibrating the spring constants of probes used for force microscopy/spectroscopy is described. It amounts to deflecting an 'unknown' cantilever with a 'standard' lever, where the standard lever has been precalibrated. The absolute and relative accuracies of the procedure are ±20-30% and ±10-20%, respectively; the former is limited by uncertainties in the determination of the spring constant for the 'standard' lever, as well as that for the 'unknown'. The method differs from others of the static deflection variety by its exploitation of the routine features of current instruments. The technique is compared with other static and dynamic methods currently being used.

https://iopscience.iop.org/article/10.1088/0957-4484/7/3/014/pdf

Determination of the spring constants of probes for force microscopy/spectroscopy

Radiation-induced reactions in chemically amplified resists based on deprotection of t-butoxycarbonyl groups have been investigated by both time-resolved (the pulse radiolysis methods) and steady-state optical absorption spectroscopy. Upon exposure of a partially tBOC-protected novolak by electron and synchrotron radiation beams, the yields of the intermediates contributing to the acid generation (phenoxyl radical and proton adducts of base resin) decreased with increasing the protection ratio of hydroxyl groups. Therefore, the efficiency of the acid generation is closely related with the protection ratio. The relation of the acid generation mechanism with the protection ratio was discussed.

Radiation-induced reactions of chemically amplified x-ray and electron-beam resists based on deprotection of t-butoxycarbonyl groups

A phase-shifting mask technique using an i-line stepper was applied to the gate formation process of AlGaAs/GaAs high electron mobility transistors (HEMTs). To obtain a fine gate pattern of less than a quarter micron, the phase-shifter edge-line mask, which has the highest resolution and wide focus margin for an isolated pattern, was used and the double exposure process was developed to form a real gate pattern. The controllable gate length was in the range of 0.50-0.15 µm. By using this technique, 0.18 µm-gate HEMTs with good and uniform microwave performances in a 3-inch wafer were obtained. This technique has great advantages for applications to microwave GaAs devices and ultrahigh-speed GaAs LSIs.

Sub-Quarter-Micron Gate Fabrication Process Using Phase-Shifting Mask for Microwave GaAs Devices

PURPOSE: To form a minute space pattern or hole pattern by providing a light transmission part in an isolated light shielding pattern and providing this light transmission part with a thin film which shifts the phase of transmitted light. CONSTITUTION: A substrate 33 of a photomask 31 is normally made of a quartz, and a light shielding pattern 35 to get the isolated light shielding pattern, namely, a space pattern of W×L is internally provided with a light transmission part 37 having prescribed size and shape. The light transmission part 37 is completely covered with a phase shifting thin film 39 which shifts the phase of the light transmitted through the light transmission part 37, and this thin film 39 is not protruded from the light shielding pattern 35. That is, the intensity of diffracted light to the isolated light shielding pattern is weakened by the light which is transmitted through the light transmission part 37 provided in this isolated pattern and has the phase shifted by the thin film 39. Thus, a minute isolated light shielding pattern is formed. COPYRIGHT: (C)1991,JPO&Japio

Photomask and pattern forming method using same

A photomask for a negative resist used for forming a resist image in the form of an isolated pattern. The photomask (40; 60; 70; 80; 90; 100; 120; 140) comprises a substrate (42; 82; 92; 102; 122; 142) transparent to an exposure light and a mask pattern (44; 62; 84 and 86; 94 and 96; 110; 132; 154) on the substrate. The mask pattern is formed of a phase-shifting layer (44; 62) alone or of a phase-shifting layer(s) (86; 96; 116; 130; 150) and a light-screening layer(s) (84; 94; 112; 124; 152). The phase-shifting layer is capable of shifting the phase of the light transmitted therethrough relatively to the phase of the light transmitted through the area of the photomask other than the area of the phase-shifting layer. A phase-shifting layer may be provided in such a way to substantially surround a light-screening layer having a width permitting of no resolution by itself. A phase-shifting layer may be provided in such a way to fill up an auxiliary aperture (114; 128; 148) provided in a light-screening layer. The portion of the phase-shifting layer filled in the aperture having a width permitting of no resolution by itself. With the use of the photomask, such a fine space or hole resist pattern as to exceed the resolution limit can be formed with excellent resolution and focus margin. A process for forming an isolated resist pattern using the photomask is also disclosed.

Phase-shifting photomask for negative resist and process for forming isolated, negative resist pattern using the phaseshifting photomask

Negative photoresist, LMR-UV, has been developed for i-line lithography. It resolves isolated 0.3 µm space and 0.35 µm hole patterns of 1.0 µm thickness by using a 0.42-numerical-aperture i-line reduction projection aligner. LMR-UV gives overhung profiles because of its large absorption coefficient of 3.8 µm-1 at the i-line. New phase-shifting mask patterns which are adapted to isolated space and hole patterns for negative resist have been developed. By use of this mask, LMR-UV clearly resolves 0.25 µm space and 0.3 µm hole patterns by using the i-line aligner. This phase-shifting mask improves both resolution and focus margin.

Yoshio Yamashita

Papers

Radiation-induced reactions of chemically amplified x-ray and electron-beam resists based on deprotection of t-butoxycarbonyl groups

Sub-Quarter-Micron Gate Fabrication Process Using Phase-Shifting Mask for Microwave GaAs Devices

Photomask and pattern forming method using same

Phase-shifting photomask for negative resist and process for forming isolated, negative resist pattern using the phaseshifting photomask

Sub-Half-Micron i-Line Lithography by Use of LMR-UV Resist