| 摘要 |
<p>A thin film (12) is formed on a substrate (11) by causing a pulsed molecular beam (5) from a source (2) to be incident on the substrate (11). The beam (5) is converted to pulses by a chopper (4). The beam (5) passes through an ionisation chamber where a part of it is ionised. The results of the ionation are amplified and converted to an electrical signal which is fed via an amplifier (15) to a measurement device (16), which also receives a signal from a photo-sensor (17) monitoring the chopper 4. The device (16) then calculates the flux and speed of the beam (5) and uses the result to control the source (2) via a controller (3) which controls the current heating the material (1) in the source (2).</p><p>The result is that a direct measurement of the flux and speed of the beam (5) can be obtained, and hence the amount of material arriving at the substrate (11) can be controlled accurately.</p> |
