Study On Inlay-structure Diamond Coatings On Copper Substrate By Doping Cr And Mold-Pressing Process

The rapid evolution of integration technology has resulted in a significant increase inmicroelectronics device density and speed. Accompanied by this device density increase is theconstant increase in power density on integrated circuit (IC) chips. Being transformed intoheat for most of the power consumed, the temperature of ICs increases quickly and lead to agreat decrease of the reliability of ICs. How to dissipate and remove the heat from ICsbecomes a key issue for the integrate density increase. Owing to the highest thermalconductivity and low thermal expansion coefficient, diamond is an idea material of first heatexchanger. Copper with high thermal conductivity and excellent processibility is good secondheat exchanger material. Depositing diamond film on copper substate promises highefficiency. of combined heat sink.However, it is diffcult to deposit diamond coating on copperdirectly because of the bad wettability between copper and diamond and large difference ofthermal expansion coefficient. An inlay structured interlayer was prepared by compositeplating-post plating and mold processing in this thesis. The diamond coating were depositedby hot filament chemical vapor deposition(HFCVD). The performance of inlayed structureCVD diamond coating was studied.The effect of Cr in addition to the substrate by differentmethonds was studied in the process of HFCVD.Two different sizes of diamond particles were dispersed on the substrate surface evenlyas seed crystal by Cu-diamond composite plating in this thesis. The inlay structure interlayerprepared by post plating was deposited in the HFCVD stove. Crystal quality、innerstress、adhesion and surface roughness were studied.As the experiment results showed, the adhesionbetween films and matrix which inlayed10μm size diamond particles was better than thatinlayed5μm. The addition Cr of post plating solution contributed to improving the adhesionbetween films and matrix. The section EDS component analysis showed little Cr in theinterface between films and martix.Mold pressing the inlay structure substrates which were post plated by10μm sizediamond particle. Crystal quality、innerstress、adhesion and surface rouhness were studiedafter CVD.Research showed the surface roughness of mold pressed substrates CVD diamond films decreased by more than half. To some extent,the adhesion between films and matrix wasimproved because of the inlay deep increasing.Copper, magnetron sputtering Cr films on copper and chormium content0.8%of Cu-Cralloy were researched as objects. The samples which diamond particles were dispersed in thediamond-achol suspension liquid. The inlayed structure interlayer prepared by moldprocessing. Research showed that the inlay structure of red copper prepared by moldprocessing had grown continuous diamond film in the process of CVD.However, the diamondfilm were dropped out after cold cutting. The magnetron sputtering Cr tended to be oxidatedinto Cr2O3in high temperature. The formation of Cr2O3is not in favour of the nucleation ofdiamond particles. The tiny chormium of Cu-Cr alloy diffused to the substate surface. And theCr reacted with the activated carbon to form Cr2C3. Tiny content of Cr2C3would increase thewettability between copper and diamond. Thereby, it would improve the adhesion betweensubstate and diamond coating.