| 摘要 |
PURPOSE:To make the pressure in a system constant and to enable the stabilization of particle beam, by constituting a flow control apparatus by arranging a pressure control device to at least one of the upstream and downstream sides of a contractible and expansible nozzle. CONSTITUTION:When a downstream chamber 4 is evacuated while fine particles are supplied into an upstream chamber 3, fine particles are injected into the downstream chamber 4 from a contractible and expansible nozzle 1 by the difference pressure between the upstream chamber 3 and the downstream chamber 4. At this time, when the pressure ratio of the pressure Po in the upstream chamber 3 and the pressure P in the downstream chamber 4 becomes a critical pressure ratio or less, fine particles injected from the nozzle 1 come to a proper expanded stream of supersonic velocity under such a condition that the pressure of an outflow port 1C comes to P to become a beam-like-stream which is, in turn, sprayed to a substrate 5. A pressure control apparatus 2 keeps the pressure in the downstream chamber 4 constant and fine particles are stably supplied into the upstream chamber 3 to stabilize the beam. |
