| 摘要 |
<p>An ion implanter has an ion source (10) and an ion beam extraction assembly (50) for extracting the ions. The extraction assembly (50) is a tetrode structure and one of the pairs of extraction electrodes (51) has left and right ports (54, 55) located in opposite sides of the ion beam emerging from the ion source (10). The left and right electrode ports (54, 55) are electrically isolated from each other and connected to independent voltage sources (210, 230). The ion implanter also has a baffle plate (60) at the entrance to a mass analyser (90) downstream of the extraction assembly (50). The baffle plate (60) is also split into two halves (60' and 60'). By measuring the beam current incident on the two halves (60', 60') of the baffle (60), the relative voltages supplied to the left and right electrode parts (54, 55) may be adjusted so as to steer the ion beam and adjust the angle of incidence of the longitudinal axis thereof relative to the input of the analysing magnet (90).</p> |
