| 摘要 |
PURPOSE:To obtain a diaphragm of a dense and even thickness composed of a diamond multi-crystal body by using a thin layer of a diamond of a density of 3.2-3.5g/cm<2>, Young's modulus of 0.5-1.2X10<12>N/m<2>. CONSTITUTION:Grains of a diamond as a base plate are collided with one another by an ultrasonic wave, and an Si wafer of a diameter of one inch and having numerous and dense and fine flaws is used. This is placed 5mm downward from a center of a plasma generated by a micro wave of 2.45GHz and a temperature of the base plate is maintained at 850 deg.C by a pyrometer measuring, a gas of CH4/H2:1:99 is conducted to produce a diamond dense and fine crystal on a surface of the base plate. After operating for 20hr, the Si wafer is dissolved by HF and a diamond thin layer is obtained. This thin layer has a base plate side surface being smooth and is a film of a multi-crystal body of 1 inch in diameter having a coarse surface, thickness of 20+ or -1mum density of rho:3.51g/cm<2>, Young's modulus of E:1X10<12>N/m<2>, specific resiliency E/rho:29X10<8> m<2>/sec. The figure shows a frequency characteristic of a film diaphragm. |
