To fabricate back side contact pads that are suitable for use in a vertical integrated circuit, vias are made in the face side of a wafer, and dielectric and contact pad metal are deposited into the vias Then the wafer back side is etched until the metal is exposed When the etch exposes the insulator at the via bottoms, the insulator is etched slower than the wafer material (eg silicon) Therefore, when the dielectric is etched off and the metal is exposed, the dielectric protrudes down from the wafer back side around the exposed metal contact pads, by about 8 μm in some embodiments The protruding dielectric portions improve insulation between the wafer and the contact pads when the contact pads are soldered to an underlying circuit In some embodiments, before the contact pads are soldered, additional dielectric is grown on the wafer back side without covering the contact pads In some embodiments, the wafer etch and the fabrication of the additional dielectric are performed one after another by a plasma process while the wafer is held in a non-contact wafer holder In some embodiments, the wafer is diced and the dice are tested before the etch The etch and the deposition of the additional dielectric are performed on good dice only In some embodiments, the dice are not used for vertical integration

Integrated circuits and methods for their fabrication

A laser beam machining method and a laser beam machining device capable of cutting a work without producing a fusing and a cracking out of a predetermined cutting line on the surface of the work, wherein a pulse laser beam is radiated on the predetermined cut line on the surface of the work under the conditions causing a multiple photon absorption and with a condensed point aligned to the inside of the work, and a modified area is formed inside the work along the predetermined determined cut line by moving the condensed point along the predetermined cut line, whereby the work can be cut with a rather small force by cracking the work along the predetermined cut line starting from the modified area and, because the pulse laser beam radiated is not almost absorbed onto the surface of the work, the surface is not fused even if the modified area is formed.

Laser processing method and laser processing apparatus

Light emitting diodes are disclosed which have increased external efficiency and are formed from silicon carbide substrates. Diodes are produced by a method which includes directing a beam of laser light at one surface of a portion of silicon carbide, and which the laser light is sufficient to vaporize the silicon carbide that it strikes to thereby define a cut in the silicon carbide portion; and then dry etching the silicon carbide portion to remove by-products generated when the laser light cuts the silicon carbide portion. The resulting diode structure includes reticulate patterned sidewalls that promote increased light emission efficiency.

High efficiency light emitting diodes

A method of producing light emitting diodes from silicon carbide with increased external efficiency is disclosed which includes directing a beam of laser light at one surface of a portion of silicon carbide, and in which the laser light is sufficient to vaporize the silicon carbide that it strikes to thereby define a cut in the silicon carbide portion; and then dry etching the silicon carbide portion to remove by-products generated when the laser light cuts the silicon carbide portion. The resulting wafer and diode structure are also dislcosed.

Method for producing high efficiency light-emitting diodes and resulting diode structures

A laser processing method which can highly accurately cut objects to be processed having various laminate structures is provided. An object to be processed comprising a substrate and a laminate part disposed on the front face of the substrate is irradiated with laser light L while a light-converging point P is positioned at least within the substrate, so as to form a modified region due to multiphoton absorption at least within the substrate, and cause the modified region to form a starting point region for cutting. When the object is cut along the starting point region for cutting, the object 1 can be cut with a high accuracy.

Laser processing method

An apparatus for forming grooves in a semiconductor wafer by the use of a laser beam includes a movable stage on which the wafer is mounted and a transparent member mounted on the stage in a sealed manner and covering the wafer A liquid is introduced into the space defined between the wafer and the transparent member

Hiroshi Suga

Papers

Apparatus for forming grooves on a wafer by use of a laser