Transfer of GaN-Based Light-Emitting Diodes From Silicon Growth Substrate to Copper

III-nitride light-emitting diodes (LEDs) grown on Si (111) substrates have the potential of low-cost manufacturing for solid-state lighting and display, by taking advantage of the well-developed IC technologies of silicon. In this letter, LEDs grown on silicon substrates were transferred onto copper substrates, to maximize light extraction and heat dissipation. On Si substrates, 300 ?? 300 ??m² multiple quantum well InGaN LEDs were first grown and processed. The top surface of the fabricated devices was then temporarily bonded to a sapphire wafer and the Si substrate was chemically etched. Ti/Al/Ti/Au layers were deposited on the backside of LEDs. An 80-??m-thick copper layer was electroplated and the temporary bonding was removed, resulting in LEDs on copper substrate. The optical output power of LEDs on copper increased by ~ 70% as compared to that of the LEDs on silicon. The improved performance was attributed to the removal of the light-absorbing Si substrate and the good thermal conductivity of copper.