摘要:

In this article, we present a theoretical and experimental study of the x‐ray emission produced by laser plasma sources in different spectral ranges appropriate for x‐ray lithography either in proximity printing (XRL) or projection (XRPL) approaches. For XRPL application, experiments using 10 ns laser pulses show that the maximum conversion efficiency in the (80–250 eV) range is attained atI=1011W cm−2whereas for 25 ns pulses andI≤6×1011W cm−2, it is still increasing with laser intensity. On the other hand, higher laser intensities are required to obtain a high conversion efficiency for XRL (0.9–1.4 keV). Efficient emission peaked at 1.1 keV can be achieved forI≥1013W cm−2with copper targets and pulse duration shorter than 5 ns. For iron line emission (peak at 0.9 keV), the laser intensity can be lower (I=5×1012W cm−2) and the pulse duration longer (τp=10 ns). Finally, we discuss the different approaches which may lead to the appropriate laser design.

ISSN:1071-1023    

DOI:10.1116/1.585921

出版商:American Vacuum Society    

年代:1992

数据来源: AIP

摘要:

We report on a study of proximity x‐ray lithography with a commercialized x‐ray stepper (Karl Suss XRS200) and synchrotron orbital radiation at Super‐ACO (Orsay, France). Special attention has been paid to the replication capabilities using SiC/W based high‐resolution x‐ray masks. The results show that proximity printing at a gap of 40 μm can result in subquarter micrometer replication. Since the resolution of the proximity printing is limited by the Fresnel diffraction, we use a double exposure technique to generate higher density and higher resolution grating structures. Fabrication of sub‐100 nm linewidth gratings has been achieved using this technique with a wide exposure latitude.

ISSN:1071-1023    

DOI:10.1116/1.585922

出版商:American Vacuum Society    

年代:1992

数据来源: AIP

摘要:

Registration accuracy, as well as resolution capability, is one of the critical factors to identify an appropriate lithography tool. For deep submicron devices represented by the 256 Mbit dynamic random access memory, an alignment accuracy of better than 30 nm is needed. In this article, the alignment accuracy of an x‐ray stepper was evaluated using the double‐exposure method with a posiresist. The alignment accuracy obtained was better than 38 nm (3σ). Moreover, making a quantitative analysis of alignment error factors, we identified the possibility of improvement toward better than 30 nm (3σ).  

ISSN:1071-1023    

DOI:10.1116/1.585923

出版商:American Vacuum Society    

年代:1992

数据来源: AIP

摘要:

We have developed a simple experimental technique for measuring the absorption spectrum of x‐ray photoresists in the region from 1000 to 3000 eV. Knowledge of the absorption characteristics of a photoresist allows selection of the most efficient range of energies to use for performing x‐ray exposures. The measurements were performed using the Medical Physics beamline on the University of Wisconsin Aladdin synchrotron source. The beamline is equipped with a lithium‐drifted silicon detector that provides an energy resolution of 150 eV. To avoid saturation of the Si(Li) detector, special ‘‘microbeams’’ of approximately 50 circulating electrons in the storage ring were employed. The beam intensity was monitored using a photodiode. The operation of the detector and associated diagnostic equipment will be described. Four by four millimeter square, 1.4 μm thick silicon nitride membranes were used as substrates for the resist films. Photoresist absorption was measured by comparing the transmission of silicon nitride membranes with and without photoresist coatings. Experimental results for both conventional and chemically amplified positive and chemically amplified negative x‐ray photoresists are presented.

ISSN:1071-1023    

DOI:10.1116/1.585924

出版商:American Vacuum Society    

年代:1992

数据来源: AIP