Si-based GaN millimeter wave transmission line structure and preparation method

Abstract

The invention discloses a Si-based GaN millimeter wave transmission line structure and a preparation method. The Si-based GaN millimeter wave transmission line structure comprises a Si substrate; an AlN nucleating layer, arranged on the Si substrate; a III-nitride transition layer, arranged on the AlN nucleating layer; a GaN buffer layer, arranged on the III-nitride transition layer; a metal ground layer over the GaN buffer layer; a dielectric insertion layer over the metal formation; a CPW over the dielectric insertion layer; and a ground wire of the CPW connected with the metal ground layerthrough the through hole in the medium insertion layer. The objective of the structure is to solve the problem of high radio frequency loss of a transmission line in millimeter wave circuit application. The invention provides a millimeter wave application-oriented transmission line structure on a Si-based GaN structure and a preparation method. A layer of metal ground is inserted between a CPW anda GaN layer to shield the influence of a p-type conducting channel at an AlN / Si interface, so that the radio frequency loss of the transmission line is reduced, and the application requirement of thetransmission line in a millimeter wave circuit is met.

Description

technical field [0001] The invention belongs to the technical field of semiconductors, and in particular relates to a Si-based GaN millimeter-wave transmission line structure and a preparation method. Background technique [0002] The third-generation semiconductor material GaN has the advantages of wide band gap, high critical breakdown field strength, high electron mobility, and high saturation electron drift velocity. It has great development potential in the field of microwave and millimeter wave high-power electronic devices and can be widely used. In aerospace, radar, 5G communication and other fields. Moreover, compared with sapphire-based GaN materials and SiC-based GaN structures, Si-based GaN structures have the advantages of large wafer size, low cost, and compatibility with Si-based CMOS (Complementary Metal Oxide Semiconductor, Complementary Metal Oxide Semiconductor) processes. It is conducive to promoting the large-scale commercial application of GaN microwav...

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Problems solved by technology

[0005] Although the preparation of the metal ground on the back of the Si substrate reduces a part of the energy loss, due to the influence of the p-type conductive channel at the AlN / Si interface in the Si-based GaN structure and the influence of the AlN nucleation layer and the buffer layer, the loss of the transmission line of the GCPW structure Still high, not enough to meet its application requirements in millimeter wave circuits, and because the metal ground on the back of the Si substrate needs to be connected to the bottom line of the CPW, the preparation process is more complicated

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