Fabrication of Diamond Membranes for X-Ray Masks by Hot-Filament Method

Abstract

Diamond thin films have been grown on a Si substrate by a hot-filament method with mixtures of CH4 and H2, and properties such as stress and optical transmittance were investigated for free-standing membrane films as a function of methane concentration (0.5-2.0%) and deposition pressure (8-80 Torr). Ellipsometric and Raman scattering measurements were also carried out to evaluate the film structure, and graphite and void components. It has been found that the loss in the optical transparency is mainly due to light scattering at the surface. It is also shown that boron doping is useful for decreasing the film resistivity, which is advantageous for electron beam (EB) writing and inspections.

Polycrystalline diamond pressure sensor

“…Film stresses were discussed by Schafer [32] and Marumoto [33]. Compressive stress occurs for film thickness under 1 pm and tensile stress for thickness greater than 1 pm.…”

Theoretical Analysis on Mechanical Deformation of Membrane-Based Photomask Blanks

“…Figure 2 shows a typical process sequence of membranebased photomask blank. 14) Firstly membrane film of such as silicon carbide (SiC) 15,16) or diamond 17,18) is deposited on the both side of Si wafer (step 1: membrane deposition). Next, the membrane on backside of the Si wafer is partly removed by dry etching (step 2: membrane etching), and then membrane window is formed by Si backside etching (step 3: back-etching).…”

Fabrication of high resolution x-ray masks using diamond membrane for second generation x-ray lithography

“…We have studied the application of diamond membranes to x-ray masks jointly with Mitsubishi Materials Corporation from the viewpoints of stiffness and resultant image placement accuracy. 12,13 In this work, we study the diamond-used x-ray mask from some standpoints. First, we calculate the relation between the x-ray absorption in the resist and the thickness of diamond membrane for the typical exposure systems in order to clarify the limit of the membrane thickness.…”