Electron beam writing techniques for fabricating highly accurate X-ray masks

• Published in: Japanese Journal of Applied Physics 1995, Vol.34 (12B), p.6738-6742
• Main Authors: KISE, K, AYA, S, YABE, H, MARUMOTO, K, HIFUMI, T, MATSUI, Y
• Format: Article
• Language: English
• Subjects: Applied sciences; Electronics; Exact sciences and technology; Microelectronic fabrication (materials and surfaces technology); Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.34.6738

The problems in electron beam writing for the membrane-process were investigated; the resist thickness on the thinned membrane was adequately uniform (3σ=0.44%), and the resultant pattern size error was negligible. Deformation due to mask chucking onto the electron beam (EB) cassette was small enough to allow production of acceptable gigabit ULSI devices. We also confirmed that the SiC membrane is durable enough for the task of membrane-process, even with thermal impact of EB energy 40 times larger than that used in conventional writing. Moreover, the improvement of pattern size accuracy by using multiple writing was investigated in detail under various conditions of the beam step size, the writing time and the resist sensitivity. The pattern width deviation was improved from 20% to 13% for 0.15 µ m line-and-space patterns by multiple writing, and was little dependent on the beam step size and the resist sensitivity.