Nissin Ion Equipment Co., Ltd.

Benjamin Thomas King

Hilton Frank Glavish

Masao Naito

Shojiro Dohi

A magnetic system for uniformly scanning an ion beam across a semiconductor wafer comprises a magnetic scanner having ac and dc coil windings each of which extend linearly along internal pole faces of a magnetic core. The ac and dc coil windings are mutually orthogonal; a time dependent magnetic component causes ion beam scanning while a substantially static (dc) field component allows the ion beam to be bent in an orthogonal plane. The current density in the ac and dc coil windings is uniformly dispersed along the pole faces leading to an improved beam spot uniformity at the wafer. The magnetic system also includes a collimator having first and second mutually opposed symmetrical dipoles defining an aperture between them. The poles of each dipole have a pole face varying monotonically and polynomially in a direction perpendicular to a central axis of the collimator: an increasing pole gap is formed towards that central axis.

Ion beam scanner for an ion implanter

An ion beam bending magnet provides a curved path through the magnet for bending a ribbon-shaped ion beam having its major cross-sectional dimension normal to the bending plane of the magnet. The magnet comprises a ferromagnetic yoke surrounding the beam path and having an internal profile in cross-section formed of four angled sides. These sides are angled to the major dimension of the ribbon beam passing through the magnet, so that the internal profile of the yoke is relatively wide in the center of the ribbon beam and relatively narrow near the top and bottom edges of the ribbon beam. Electrical conductors against the internal surfaces of the yoke provide a uniform distribution of electrical current per unit length along the angled sides of the profile, providing a substantially uniform magnetic bending field within the magnet yoke.

Growing community of inventors

Lower Hutt, New Zealand

Benjamin Thomas King