Wafer level GaN device substrate transfer method

Abstract

The invention discloses a transfer method based on a wafer level GaN device original substrate, and belongs to the technical field of semiconductor technology. The surface of an original film is covered with a removable thicker protection supporting layer, and after the original substrate is removed, two wafers are bonded directly. The method comprises the following steps: (1) enabling the surfaceof a wafer level GaN device after front face technology to be covered with the protection supporting layer; (2) removing the original substrate; (3) cleaning the back face of a wafer and the surfaceof an Si substrate to be transferred; (4) carrying out N2 gas plasma processing on the back face of the wafer; (5) carrying out O2 gas plasma processing on the surface of the Si wafer; (6) putting thetwo parts into an ammonia water solution for prebonding; (7) applying external force to a laminated sample in an N2 environment for bonding; (8) carrying out low temperature annealing processing on the bonded wafer; (9) exposing the annealed wafer, and then putting the exposed wafer into a developing solution to resolve and remove a surface protective layer. According to the method, the substratetransfer of the GaN device can be realized.

Description

technical field [0001] The invention belongs to the technical field of semiconductor technology, and in particular relates to a method for substrate transfer of a wafer-level GaN device. Background technique [0002] Gallium nitride (GaN) is a very attractive material for high power and high frequency devices such as high electron mobility transistors (HEMTs) due to their high electron saturation velocity and wide bandgap. Currently, epitaxial GaN can be grown on heterogeneous substrates such as silicon (Si), sapphire (Al 2 o 3 ) or silicon carbide (SiC) and on homogeneous substrates. GaN grown on Si is most preferred because Si wafers are available in larger diameters and have higher thermal conductivity than sapphire. However, the quality of epitaxial GaN grown on Si is limited due to high threading dislocation density (TDD) and cracks due to large thermal and lattice mismatch, which lead to poor device performance and low yield . [0003] Recently, several epitaxial ...

AI Technical Summary

Problems solved by technology

[0006] The object of the present invention is to provide a method for substrate transfer of a wafer-level GaN device, through surface spin-coating thicker photosensitive BCB, and then forming a surface-activated bonding method of a protective support layer, to achieve on a heterogeneous substrate ( The substrate transfer of GaN devices made of Si, sapphire, SiC) and homogeneous substrate (GaN) epitaxially grown GaN materials meets the RF performance of GaN HMET devices and HBT (heterojunction bipolar transistor) devices to solve The problem of performance degradation due to device temperature rise when the device is operating at high power

Images