Patent application number | Description | Published |
20090250713 | Reflective Contact for a Semiconductor Light Emitting Device - A light emitting device includes a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region. A contact is formed on the semiconductor structure, the contact comprising a reflective metal in direct contact with the semiconductor structure and an additional metal or semi-metal disposed within the reflective metal. In some embodiments, the additional metal or semi-metal is a material with higher electronegativity than the reflective metal. The presence of the high electronegativity material in the contact may increase the overall electronegativity of the contact, which may reduce the forward voltage of the device. In some embodiments, an oxygen-gathering material is included in the contact. | 10-08-2009 |
20100006864 | IMPLANTED CONNECTORS IN LED SUBMOUNT FOR PEC ETCHING BIAS - A sapphire growth substrate wafer has epitaxially grown over it N-type layers, an active layer, and P-type layers to form GaN LEDs. Each LED is a flip-chip with its cathode contact and anode contact formed on the same side. The wafer is then diced to separate out the LEDs. A P-type silicon submount wafer has N-type doped interconnect regions for interconnecting all the cathode contacts together after the LEDs are mounted on the submount wafer. The sapphire substrate is then removed by a laser lift-off process. A bias voltage is then applied to the cathode contacts via the interconnect regions to bias the N-type layers for a photo-electrochemical etching process that roughens the exposed layer for increased light extraction. The submount wafer is then diced, cutting through the doped interconnect regions. | 01-14-2010 |
20100109030 | SERIES CONNECTED FLIP CHIP LEDS WITH GROWTH SUBSTRATE REMOVED - LED layers are grown over a sapphire substrate. Individual flip chip LEDs are formed by trenching or masked ion implantation. Modules containing a plurality of LEDs are diced and mounted on a submount wafer. A submount metal pattern or a metal pattern formed on the LEDs connects the LEDs in a module in series. The growth substrate is then removed, such as by laser lift-off. A semi-insulating layer is formed, prior to or after mounting, that mechanically connects the LEDs together. The semi-insulating layer may be formed by ion implantation of a layer between the substrate and the LED layers. PEC etching of the semi-insulating layer, exposed after substrate removal, may be performed by biasing the semi-insulating layer. The submount is then diced to create LED modules containing series-connected LEDs. | 05-06-2010 |
20100207157 | LED ASSEMBLY HAVING MAXIMUM METAL SUPPORT FOR LASER LIFT-OFF OF GROWTH SUBSTRATE - Described is a process for forming an LED structure using a laser lift-off process to remove the growth substrate (e.g., sapphire) after the LED die is bonded to a submount. The underside of the LED die has formed on it anode and cathode electrodes that are substantially in the same plane, where the electrodes cover at least 85% of the back surface of the LED structure. The submount has a corresponding layout of anode and cathode electrodes substantially in the same plane. The LED die electrodes and submount electrodes are ultrasonically welded together such that virtually the entire surface of the LED die is supported by the electrodes and submount. Other bonding techniques may also be used. No underfill is used. The growth substrate, forming the top of the LED structure, is then removed from the LED layers using a laser lift-off process. The extremely high pressures created during the laser lift-off process do not damage the LED layers due to the large area support of the LED layers by the electrodes and submount. | 08-19-2010 |
20110057569 | ZENER DIODE PROTECTION NETWORK IN SUBMOUNT FOR LEDS CONNECTED IN SERIES - A transient voltage suppressor circuit is disclosed for a plurality (N) of LEDs connected in series. Only one zener diode is created for connection to each node between LEDs, and a pair of zener diodes (the “end” zener diodes) are connected to the two pins (anode and cathode pads) of the series string. Therefore, only N+1 zener diodes are used. The end zener diodes (Q | 03-10-2011 |
20110136273 | REFLECTIVE CONTACT FOR A SEMICONDUCTOR LIGHT EMITTING DEVICE - A light emitting device includes a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region. A contact is formed on the semiconductor structure, the contact comprising a reflective metal in direct contact with the semiconductor structure and an additional metal or semi-metal disposed within the reflective metal. In some embodiments, the additional metal or semi-metal is a material with higher electronegativity than the reflective metal. The presence of the high electronegativity material in the contact may increase the overall electronegativity of the contact, which may reduce the forward voltage of the device. In some embodiments, an oxygen-gathering material is included in the contact. | 06-09-2011 |
20110297979 | PASSIVATION FOR A SEMICONDUCTOR LIGHT EMITTING DEVICE - In embodiments of the invention, a passivation layer is disposed over a side of a semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region. A material configured to adhere to an underfill is disposed over an etched surface of the semiconductor structure. | 12-08-2011 |
20120025231 | SERIES CONNECTED FLIP CHIP LEDS WITH GROWTH SUBSTRATE REMOVED - LED layers are grown over a sapphire substrate. Individual flip chip LEDs are formed by trenching or masked ion implantation. Modules containing a plurality of LEDs are diced and mounted on a submount wafer. A submount metal pattern or a metal pattern formed on the LEDs connects the LEDs in a module in series. The growth substrate is then removed, such as by laser lift-off. A semi-insulating layer is formed, prior to or after mounting, that mechanically connects the LEDs together. The semi-insulating layer may be formed by ion implantation of a layer between the substrate and the LED layers. PEC etching of the semi-insulating layer, exposed after substrate removal, may be performed by biasing the semi-insulating layer. The submount is then diced to create LED modules containing series-connected LEDs. | 02-02-2012 |
20130252358 | PASSIVATION FOR A SEMICONDUCTOR LIGHT EMITTING DEVICE - In embodiments of the invention, a passivation layer is disposed over a side of a semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region. A material configured to adhere to an underfill is disposed over an etched surface of the semiconductor structure. | 09-26-2013 |