Cree Gmbh

Max Batres

Shuji Nakamura

Steven P DenBaars

James Ibbetson

Michael Coulter

Ting Li

Bernd P Keller

Nicholas William Medendorp, Jr

Adam William Saxler

Ashay Chitnis

Steven Denbaars

Mike Coulter

A wire-bond free semiconductor device with two electrodes both of which are accessible from the bottom side of the device. The device is fabricated with two electrodes that are electrically connected to the oppositely doped epitaxial layers, each of these electrodes having leads with bottom-side access points. This structure allows the device to be biased with an external voltage/current source, obviating the need for wire-bonds or other such connection mechanisms that must be formed at the packaging level. Thus, features that are traditionally added to the device at the packaging level (e.g., phosphor layers or encapsulants) may be included in the wafer level fabrication process. Additionally, the bottom-side electrodes are thick enough to provide primary structural support to the device, eliminating the need to leave the growth substrate as part of the finished device.

Wire bond free wafer level LED

An LED having a p-type layer of material with an associated p-contact, an n-type layer of material with an associated n-contact and an active region between the p-type layer and the n-type layer, includes a roughened emitting-side surface to further enhance light extraction.

LED with surface roughening

The surface morphology of an LED light emitting surface is changed by applying a reactive ion etch (RIE) process to the light emitting surface. Etched features, such as truncated pyramids, may be formed on the emitting surface, prior to the RIE process, by cutting into the surface using a saw blade or a masked etching technique. Sidewall cuts may also be made in the emitting surface prior to the RIE process. A light absorbing damaged layer of material associated with saw cutting is removed by the RIE process. The surface morphology created by the RIE process may be emulated using different, various combinations of non-RIE processes such as grit sanding and deposition of a roughened layer of material or particles followed by dry etching.

LED with substrate modifications for enhanced light extraction and method of making same

A light emitting diode having a vertical orientation with an ohmic contact on portions of a top surface of the diode and a reflective layer adjacent the light emitting region of the diode. This light emitting diode includes a confinement structure. The confinement structure may be an opening in the reflective layer generally beneath the top ohmic contact that defines a non-contact area between the reflective layer and the light emitting region of the diode to encourage current flow to take place other than at the non-contact area to in turn decrease the number of light emitting recombinations beneath the ohmic contact and increase the number of light emitting recombinations in the areas not beneath said ohmic contact. The LED may include roughened emitting surfaces to further enhance light extraction.

LED with current confinement structure and surface roughening

An LED having a p-type layer of material with an associated p-contact, an n-type layer of material with an associated n-contact and an active region between the p-type layer and the n-type layer, includes a confinement structure that is formed within one of the p-type layer of material and the n-type layer of material. The confinement structure is generally aligned with the contact on the top and primary emission surface of the LED and substantially prevents the emission of light from the area of the active region that is coincident with the area of the confinement structure and the top-surface contact. The LED may include a roughened emitting-side surface to further enhance light extraction.

LED with a current confinement structure aligned with a contact

A susceptor for holding semiconductor wafers in an MOCVD reactor during growth of epitaxial layers on the wafers is disclosed. The susceptor comprises a base structure made of a material having low thermal conductivity at high temperature, and has one or more plate holes to house heat transfer plugs. The plugs are made of a material with high thermal conductivity at high temperatures to transfer heat to the semiconductor wafers. A metalorganic chemical vapor deposition reactor is also disclosed utilizing a susceptor according to the present invention.

Susceptor for MOCVD reactor

The present invention discloses a susceptor mounting assembly for holding semiconductor wafers in an MOCVD reactor during growth of epitaxial layers on the wafers, that is particularly adapted for mounting a susceptor in an inverted type reactor chamber. It includes a tower having an upper and lower end with the upper end mounted to the top inside surface of the reactor chamber and a susceptor is arranged at the tower's lower end. Semiconductor wafers are held adjacent to the susceptor such that heat from the susceptor passes into wafers. A second embodiment of a susceptor mounting assembly according to the invention also comprises a tower having an upper and lower end. The tower's upper end is mounted to the top inside surface of the reactor chamber. A susceptor is housed within a cup and the cup is mounted to the tower's lower end.

Susceptor apparatus for inverted type MOCVD reactor

A semiconductor fabrication reactor according to the invention comprises a rotatable susceptor mounted to the top of a reactor chamber. One or more wafers are mounted to a surface of the susceptor and the rotation of the susceptor causes the wafers to rotate within the chamber. A heater heats the susceptor and a chamber gas inlet allows semiconductor growth gasses into the reactor chamber to deposit semiconductor material on said wafers. A chamber gas outlet is included to allow growth gasses to exit the chamber. In a preferred embodiment, the inlet is at or below the level of said wafers and the outlet is preferably at or above the level of the wafers. A semiconductor fabrication system according to the invention comprises a source of gasses for forming epitaxial layers on wafers and a source of gasses for dopants in said epitaxial layers. A gas line carries the dopant and epitaxial source gasses to a reactor for growing semiconductor devices on wafers, and the source gasses in the gas line are injected into the reactor chamber through a reactor inlet. The reactor comprises an inverted susceptor mounted in a reactor chamber that is capable of rotating. One or more wafers are mounted to a surface of the susceptor, the rotation of the susceptor causing the wafers to rotate within the chamber. A heater heats the susceptor and the source gasses deposit semiconductor material on the wafers.

Apparatus for inverted multi-wafer MOCVD fabrication

The surface morphology of an LED light emitting surface is changed by applying processes, such as a reactive ion etch (RIE) process to the light emitting surface. In one embodiment, the changed surface morphology takes the form of a moth-eye surface. The surface morphology created by the RIE process may be emulated using different combinations of non-RIE processes such as grit sanding and deposition of a roughened layer of material or particles followed by dry etching.

A susceptor for holding semiconductor wafers in an MOCVD reactor during growth of epitaxial layers on the wafers is disclosed. The susceptor comprises a base structure made of a material having low thermal conductivity at high temperature, and has one or more plate holes to house heat transfer plugs. The plugs are made of a material with high thermal conductivity at high temperatures to transfer heat to the semiconductor wafers. A metalorganic organic chemical vapor deposition reactor is also disclosed utilizing a susceptor according to the present invention.

Growing community of inventors

Santa Barbara, CA, United States of America

Max Batres