Due to its excellent thermal conductivity and insulation properties, diamond has become a key material for heat dissipation in next-generation high-power chips and devices. Bonding chips directly to diamond to reduce junction temperature is considered an ideal thermal management solution for high-performance chips and 3D packaging. Typically, diamond thin films are synthesized on a silicon substrate, which is subsequently removed via chemical etching to yield a “self-supporting” diamond film. Previously, a research team at the Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, successfully fabricated a 4-inch “self-supporting” diamond ultra-thin film with ultra-low warpage.
Laser peripheral grooving; diamond film peeling
Recently, the team has made further progress in high-efficiency peeling technology for diamond ultrathin films, developing a “self-peeling” technique for 4-inch-class diamond ultrathin films with ultra-low warpage. Through precise control of the initial nucleation and growth of the diamond film, as well as process innovations, the synthesized 4-inch diamond film (thickness <100 μm) can be perfectly and damage-free separated from the Si substrate solely by the film’s own weight—without any external force—after grooving, resulting in a flat “self-supporting” ultra-thin film. This technology reduces the peeling time from the several hours previously required for etching to just a few minutes, thereby lowering costs and increasing speed. It also overcomes the environmental hazards associated with chemical etching and opens up a new, efficient, and green manufacturing pathway for high-thermal-conductivity, “self-supporting” diamond ultrathin films.
MPCVD synthesis of 12-inch diamond films; synthesis of 5 4-inch diamond films using a single system
At the same time, the team expanded the deposition area of the 915 MHz high-power MPCVD system to 12 inches, achieving the simultaneous synthesis of five 4-inch diamond films with low stress and ultra-low warpage on a single machine. Combined with the aforementioned highly efficient “self-peeling” technology, this has laid the equipment and process foundation for the industrial-scale batch production of “self-supporting” diamond films.
