Abstract:
An improved process for electroplating bonding pads, such as of gold, onto semiconductor devices is disclosed. Upon electrically connecting a masked semiconductor body and a suitable anode to the negative and positive terminals respectively of a power supply and submerging the wafer and anode into a suitable electrolyte, a modulated, rather than direct, current is applied to the electrolyte. A low stress, fine grain bonding pad layer is provided and, unexpectedly, non-planarities in the semiconductor body surface having a depth of about 1-3 microns can be substantially planarized when the thickness of the layer deposited is about 6-8 microns or more.
Abstract:
An improved method of selectively depositing coatings onto bodies of semiconductor material employs as a protective mask an alkyl ester of a sulfosuccinate salt. The mask material is applied to areas which are to be kept free of the coatings. The overspray of a desired coating, onto the protective mask is deposited in a cracked, non-continuous manner, as opposed to the smooth crystalline layer being deposited over the semiconductor body. This overspray coating can be readily removed.
Abstract:
The invention is an improved light emitting device comprising a light emitting element mounted on a header wherein the improvement comprises a thin layer of copper overlying the surface of the header including both the base and the stud. A large increase in the yield of useable devices is obtained for a light emitting element mounted on the header which emits between about 1.0 and about 1.7 micrometers.
Abstract:
A single crystal layer of either cadmium sulfide or an alloy of cadmium sulfide and indium phosphide is epitaxially deposited on a substrate of cadmium sulfide by liquid phase epitaxy using indium as the solvent.
Abstract:
An improved method of mounting electroluminescent semiconductor laser devices onto heatsinks, wherein easy subsequent location of the lasing spot of the laser is provided, is disclosed. The method comprises placing a reference mark on the front of the heatsink, wetting solder to the heatsink and allowing it to harden, contacting the laser device to the hardened solder, applying current to the laser device to cause light emission, aligning the lasing spot to the reference mark and bonding the laser device to the heatsink while maintaining such alignment.
Abstract:
An apparatus and method for imparting a sharp, defect-free outside corner of a desired angle to a metal workpiece are disclosed. The apparatus comprises two separate cutting tools, each with a distinct cutting direction. The tools are juxtaposed such that their leading surfaces are adjacent to each other and that their respective cutting edges intersect at the desired angle. This provides that the cutting directions of each tool are opposite one another. In using the improved cutting apparatus, the workpiece is secured and the apparatus must be movable along the x, y and z axes. By cutting the first and second surfaces of the workpiece in sequence with the first and second cutting edges of the present apparatus respectively, a sharp defect-free corner of the desired angle can be imparted to the workpiece. A specific application for the present invention is in the fabrication of intricate copper products, such as heatsinks for semiconductor devices.
Abstract:
A wide band gap semiconductor alloy having a combination of P, In, Te, and Zn is formed by liquid phase epitaxy on an InP substrate. This alloy can be used for the formation of p-n junctions.
Abstract:
A body including P type indium phosphide has an ohmic contact thereon of an alloy of by weight 81% to 86% gold (Au), 11% to 14% germanium (Ge) and 2% to 5% zinc (Zn). This contact has a low resistance and good adhesion to the indium phosphide body.
Abstract:
A device header with a multilayer coating overlying its entire surface, and a method of making said header, are disclosed. The multilayer coating comprises an electrolytic nickel layer and a gold layer in the device mounting area of the header, whereas the rest of the header is coated with electroless nickel, a first gold layer, electrolytic nickel, and a second gold layer. In the fabrication, the electroless nickel layer is deposited over the entire header followed by the first gold layer. Upon removing these layers from the device mounting area, the first gold layer remaining on the rest of the header acts as a mask for the etching of the mounting area preparatory to deposition of electrolytic nickel and the second gold layer. The header has the advantage of the excellent coverage of electroless nickel over most of its surface, but with the advantage of high purity electrolytic nickel in the device mounting area.
Abstract:
An improved burnishing method suitable for planarizing bonding pads on fragile semiconductor devices is disclosed. The method comprises imparting scratches of predetermined depth and spacing onto a glass slide. The bonding pad surface is contacted to the scratched glass surface under a desired pressure and a relative motion is established therebetween. The motion is continued until a smooth, defect-free bonding pad surface has been provided.