| Electron beam lithography(EBL) plays an irreplaceable role in integrated circuit photomask manufacturing field of micro-nano system, it is a key technology in decreasing feature size, meanwhile, it is also an indispensable fabrication method in nanoelectronics, nano-optics and manufacture of quantum structure, etc. The properties of EBL not only depend on the condition of electrooptical system, the ambient temperature, the magnetic field, the control of process conditions has also become essential when the feature size down to one hundred nanometers and below. For example, charging effect exacerbates the stitching errors of resist pattern; collapse and adhesion of resist pattern with high aspect ratio(HAR) restrict the subsequent etching process; proximity effect restricts the resolution and affects the quality of resist pattern. In order to improve the precision and quality of resist pattern effectively, the key technologies of EBL and its applications were studied systematically in this paper.In this paper, three key technologies of EBL were studied in detail, which is the charging effect on insulating substrate, collapse and adhesion of resist pattern with HAR and resolution decline caused by proximity effect. PMMA, HSQ and SX AR-P 6200 were used to find out the factors that affect the quality of resist pattern; the mechanisms and solutions were discussed and characterized by means of the physical-chemical analysis; experiment methods and process flow were designed. By means of establishing models of charge accumulation, collapse and adhesion of resist pattern with HAR, electrons scattering in substrate, and using methods that spin-coated conductive resist, microwave heating and combination of process optimization and simulation. Three resists were detected, the performance test and analysis were executed, and the exposure mechanisms were discussed. The main contents are as follows:1. Several key technologies in nanoscale EBL were summarized. Based on massive experimental results, the cause mechanisms and methods to solve the problem are analyzed and presented.2. The charging effect of EBL on insult substrates was discussed. Simulation and physical model were constructed to solve the issue that using metal layer cannot fully disperse the accumulated residual charges. A method using the water-soluble coating which full of conductive composite particles was presented, which can effectively solve the problem caused by charging effect.3. To solve the problem of high aspect radio photoresist collapse and adhesion caused by surface tension of water after development process, a method using microwave drying the resist pattern after development was presented and the mechanism was fully discussed. The rotational motion of water molecules under alternating electric field breaks the hydrogen bonding to diminish the water clusters, and then reduces the surface tension of water. The experiment results obtained with microwave drying method indicate that microwave heating has good effects to achieve high aspect radio resist pattern.4. Proximity effect of EBL was studied by both Monte Carlo simulation and processing experiment. The elements which affect forward scattering and back scattering were analyzed from process conditions and electron optical system. Considering the fabrication of typical lithography pattern, a method adjusted the exposure dose to optimize the proximity effect was studied based on the combination of the simulation and lithography experiment. Both initial and optimized experiment results are compared to determine the optimal process.The results show that: spin-coated conductive resist above the resist surface can alleviate stitching errors effectively caused by charging effect and ensure the accuracy of overlay; microwave heating and drying resist pattern with high aspect ratio after development can obtain resist lines with 260 nm high, 16 nm width and pillars with 260 nm high, 20 nm diameter; through the combination of optimizing process conditions and software calibration, the quality of resist pattern was improved significantly.
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