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    Application of SIL based Near Field Recording Technology to High Speed Nano Patterning
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    Photoresist
    Line width
    Nanometre
    Immersion lithography
    A novel double‐layer resist method was presented in this work to decrease the negative photoresist scum. Positive photoresist was chosen as the bottom layer resist and negative photoresist as the top layer resist. This work studied the effect of viscosity and thickness of bottom layer resist on the mean number of scum. The experiment shows that the low viscosity positive photoresist AZ703, with the spin speed of 3000 r/min and the thickness of 1.10 um, had prominent effect on the removal of photoresist. To minimise the area of the top layer contact with substrate and further reduce the scum, 8 µm was selected as the optimal retracting distance d of the bottom layer resist.
    Photoresist
    Double layer (biology)
    Citations (0)
    Subsequent to 45 nm node, immersion lithography using topcoat process is approaching its next step for mass production. However, microfabrication using immersion topcoat leads to increase in cost due to increase in process steps. In order to deal with this problem, high throughput scanners equipped with a wafer stage which moves at higher speed are under development. Furthermore, as resist process compatible with such high speed scanners, non-topcoat resist is available and seems promising in reducing costs of the resist process. Non-topcoat resist contains hydrophobic additives which are eccentrically located near the film surface. Because non-topcoat resist enables the formation of a more hydrophobic surface, non-topcoat resist process is more suitable for high-speed scanning than topcoat resist process. In the topcoat process, the function of topcoat material and resist material is separated. That is, the resist material and the topcoat material are responsible for lithographic performance and immersion scanning performance, respectively. However, the non-topcoat resist is expected both performances. That is, the non-topcoat resist are required a fine resist profile, small LWR, and low development defects at high speed immersion scanning. In this paper, we report the application of non-topcoat resist in 22 nm node devices. We investigate the influence of hydrophobic additives on imaging performance in several base polymers. Additionally, the influence of chemical species, molecular weight and amount of hydrophobic additive are investigated. Scan performance is also estimated by dynamic receding contact angle using pin scan tool. 22nm node imaging performance is evaluated using Nikon NSRS610C. The surface characteristics and lithographic performance of non-topcoat resist for 22 nm node devices are discussed.
    Immersion lithography
    Photoresist
    Citations (2)
    Recent progress in semiconductor devices has been remarkable. With the appearance of VLSI, production of devices has shifted from the 64K bit to the 256K bit. Reductions in size on the microfabrication have been achieved, from 2.5 μm for the 64K bit to 2.0 μm for the 256K bit. For 1 mega bit devices, further reduction to 1 μm has approached the limit for photoresist fabrication. Submicron fabrication will require special processing techniques.The following is a brief explanation of high resolution resists, including photoresist, Deep UV resist, electron beam resist, X-ray resist, and plasma-developable resist.
    Photoresist
    Semiconductor device fabrication
    Bit (key)
    F2 lithography and 193nm immersion lithography are considered candidates for 65nm node lithography technology. Of these two, 193nm immersion lithography, the latest incarnation of ArF lithography, has attracted more attention. Immersion lithography is different from conventional dry lithography in that the resist is exposed in liquid. Thus, the resist materials leaching from the resist film during exposure and the dissolution of acids generated by the exposure cause problems. Particularly, the resist materials leaching tends to contaminate the surface of the lens. We have been conducting studies on the leaching during exposure using the QCM method. In the present work, we apply this method to the immersion exposure. We report here the results of an in-situ measurement of the resist mass change during immersion exposure and discuss our analysis regarding the resist materials leaching from the resist film during the exposure.
    Immersion lithography
    Extreme Ultraviolet Lithography
    Immersion
    Citations (2)
    Abstract Optical lithography with an ArF excimer laser (193 nm) can produce sub 100nm patterns. Without the reduction of wavelength, further increase in resolution is expected by employing an immersion technique in which a liquid medium is filled between the objective lens and underlying photoresist. In this case, resolution can be enhanced through the increase of numerical aperture. However, in order for immersion lithography to be successful, many problems associated with the liquid environment need to be solved. One of the serious problems is the interaction between liquid and photoresist. Liquid may penetrate into the photoresist and cause leaching problem. This in turn modifies the physical and chemical properties of the photoresist. Thus, it is important to monitor the modification of the photoresist by immersion liquid. In this work, spectroscopic ellipsometry and imaging ellipsometry are used to investigate the absorption of liquid by photoresist as well as top coat which is used to prevent water penetration into underlying photoresist. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
    Photoresist
    Immersion lithography
    Immersion
    Ellipsometry
    Numerical aperture
    Citations (0)
    A commercially available positive photoresist, Polychrome 129 SF, has been evaluated as both a positive electron beam resist and photoresist. The photoresist sensitivity, measured uniquely for a given developer based upon image dimensional control, is determined to be less than that of AZ 1350, under as nearly equivalent conditions as possible. The E-beam resist sensitivity is lower than that of PMMA reference, but the resist possesses good resolution. Near vertical edge wall profiles are obtained for 1-micrometer lines, but no undercutting is ever achieved regardless of electron charge density magnitude. The resist is capable of submicron line and space E-beam resolution, and 0.50-0.75 micrometer wide isolated line patterns can be routinely achieved.
    Photoresist
    Micrometer
    Polychrome
    Citations (0)
    ArF immersion lithography has been introduced in mass production of 55nm node devices and beyond as the post ArF dry lithography. Due to the existence of water between the resist film and lens, we have many concerns such as leaching of PAG and quencher from resist film into immersion water, resist film swelling by water, keeping water in the immersion hood to avoid water droplets coming in contact with the wafer, and so on. We have applied to the ArF dry resist process an immersion topcoat (TC) process in order to ensure the hydrophobic property as well as one for protecting the surface. We investigate the TC-less resist process with an aim to improve CoO, the yield and productivity in mass production of immersion lithography. In this paper, we will report TC-less resist process development for the contact layer of 40nm node logic devices. It is important to control the resist surface condition to reduce pattern defects, in particular in the case of the contact layer. We evaluated defectivity and lithography performance of TC-less resist with changing hydrophobicity before and after development. Hydrophobicity of TC-less resist was controlled by changing additives with TC functions introduced into conventional ArF dry resist. However, the hydrophobicity control was not sufficient to reduce the number of Blob defects compared with the TC process. Therefore, we introduced Advanced Defect Reduction (ADR) rinse, which was a new developer rinse technique that is effective against hydrophobic surfaces. We have realized Blob defect reduction by hydrophobicity control and ADR rinse. Furthermore, we will report device performance, yield, and immersion defect data at 40nm node logic devices with TC-less resist process.
    Immersion lithography
    Immersion
    Photoresist
    Process window
    Citations (5)