Low-temperature direct bonding of InP and diamond substrates under atmospheric conditions

Abstract

An InP substrate was directly bonded on a diamond heat spreader for efficient heat dissipation. The InP surface activated by oxygen plasma and the diamond surface cleaned with an NH3/H2O2 mixture were contacted under atmospheric conditions. Subsequently, the InP/diamond specimen was annealed at 250 °C to form direct bonding. The InP and diamond substrates formed atomic bonds with a shear strength of 9.3 MPa through an amorphous intermediate layer with a thickness of 3 nm. As advanced thermal management can be provided by typical surface cleaning processes followed by low-temperature annealing, the proposed bonding method would facilitate next-generation InP devices, such as transistors for high-frequency and high-power operations.

(Invited, Digital Presentation) Low-Temperature Direct Bonding of Wide-Bandgap Semiconductor Substrates

“…This layer is mainly composed of SiOx. In addition, an indium phosphide (InP) substrate can form atomic bonds with the diamond substrate 26 . The amorphous intermediate layer with a thickness of ~3 nm was present at the bonding interface.…”

Simple Low-Temperature GaN/Diamond Bonding Process with an Atomically Thin Intermediate Layer

“…The purpose of this study was to design a low-temperature bonding process for GaN and diamond surfaces under atmospheric conditions without a thick intermediate oxide layer. Our research group developed low-temperature bonding of the diamond substrate surface OH-terminated using oxidizing solutions, , including an NH 4 OH/H 2 O 2 mixture (i.e., SC1), with other semiconductor materials (e.g., Si, , InP, and Ga 2 O 3 ). In addition, the SiC substrate OH-terminated by removing the native oxide layer with HF acid could form atomic bonds with Ga 2 O 3 through an ∼1 nm-thick amorphous intermediate layer .…”