Improvement of Uniformity of Through-Hole Coverage
Original Publication Date: 1987-Sep-01
Included in the Prior Art Database: 2005-Feb-01
A mechanism to improve the copper coverage of through-holes with a sputtering technique is accomplished using a shield to more accurately direct the sputtered particles. The process is as follows. The material to be sputtered is the cathode plate 1 (Fig. 1). With a magnetic field surrounding cathode plate 1 and the North Pole at the center, the positive particles are accelerated toward the cathode 1. When these particles collide with the plate 1, electrons and neutral atoms are sputtered out from the cathode 1 (the motion of the sputtered electrons is affected by electric and magnetic fields). Part of the electrons will fall back due to Larmor Motion. The sputtered neutral atoms or atoms that are not affected by either the electric or magnetic fields will travel out in a straight line and arrive at the anode, i.e.