Brush pressure control system for chemical and mechanical treatment of semiconductor surfaces

The present invention relates generally to an apparatus used to treat semiconductor wafer surfaces. More particularly, the present invention is an apparatus, for treating spinning semiconductor wafer surfaces, in which there is provided a head, for contacting the surface of the wafer, having attached thereto a first means for setting the head against the wafer surface with a selected predetermined force and a second means for temporarily and selectively altering the selected predetermined force set by the first means without altering the setting established by said first means. A semiconductor wafer chemical mechanical treatment apparatus having a sectional extended arm carrying a head. The sectional arm is comprised of a fixed yoke and an elongated arm positioned in said yoke on a pivot. The elongated arm carries a first means thereon for establishing and maintaining a given loading or pressure on the head. A second means, is positioned on the yoke, adjacent to the elongated arm for temporarily altering the given loading or pressure on the head established by the first means without disturbing the setting of the first means such that when the second means is reset the given head load or pressure established by said first means is automatically restored.