The concept of X-ray generation in a Spherical Pinch machine was presented at the 1991 SPIE conference (Proc. SPIE, Vol. 1465, p. 318, 1991). The machine is a pulsed power device which drives strong spherically imploding shock waves to create a highly compressed hot plasma of small size which acts like a blackbody radiator. At the present time the machine is operating at an input electrical energy of 18 kJ and is capable of reaching 34 kJ. An efficiency of about 20% has been measured for the transfer of electrical energy to the plasma. The radiation output of the machine ranges over a broad spectrum which peaks near the deep UV (100 eV - 150 eV). Therefore the machine is useful for applications such as UV and deep UV lithography, in addition to soft X-ray lithography. The dosimetry analysis shows that about 100 mJ/cm2 of UV and deep UV and about 3 - 5 mJ/cm2 of soft X-rays per single discharge is available at a distance of 20 cm from the source. The radiation output is now being optimized in order to reach the design level of 10 mJ/cm2/discharge in the soft X- ray region of the blackbody spectrum. The advantages of the machine are, besides compactness and cost effectiveness, relatively long pulse duration (approximately 10 microsecond(s) ec) and low peak power at the mask and wafer. The machine is capable of operating at a repetition rate of 0.1 Hz. A new machine with higher input energy and repetition rate is being designed and constructed and is expected to generate about 12 mJ/cm2/discharge in the soft X-ray region of the spectrum at a distance of 30 cm from the source.

Date Published: 9 July 1992
PDF: 8 pages
Proc. SPIE 1671, Electron-Beam, X-Ray, and Ion-Beam Submicrometer Lithographies for Manufacturing II, (9 July 1992); doi: 10.1117/12.136028

Published in SPIE Proceedings Vol. 1671:
Electron-Beam, X-Ray, and Ion-Beam Submicrometer Lithographies for Manufacturing II
Martin C. Peckerar, Editor(s)