Diamond is an exciting material with many outstanding properties; see, for example Field J E (ed) 1979 The Properties of Diamond (London: Academic) and Field J E (ed) 1992 The Properties of Natural and Synthetic Diamond (London: Academic). It is pre-eminent as a gemstone, an industrial tool and as a material for solid state research. Since natural diamonds grew deep below the Earth's surface before their ejection to mineable levels, they also contain valuable information for geologists. The key to many of diamond's properties is the rigidity of its structure which explains, for example, its exceptional hardness and its high thermal conductivity. Since 1953, it has been possible to grow synthetic diamond. Before then, it was effectively only possible to have natural diamond, with a small number of these found in the vicinity of meteorite impacts. Techniques are now available to grow gem quality synthetic diamonds greater than 1 carat (0.2 g) using high temperatures and pressures (HTHP) similar to those found in nature. However, the costs are high, and the largest commercially available industrial diamonds are about 0.01 carat in weight or about 1 mm in linear dimension. The bulk of synthetic diamonds used industrially are 600 µm or less. Over 75% of diamond used for industrial purposes today is synthetic material. In recent years, there have been two significant developments. The first is the production of composites based on diamond; these materials have a significantly greater toughness than diamond while still maintaining very high hardness and reasonable thermal conductivity. The second is the production at low pressures by metastable growth using chemical vapour deposition techniques. Deposition onto non-diamond substrates was first demonstrated by Spitsyn et al 1981 J. Cryst. Growth 52 219–26 and confirmed by Matsumoto et al 1982 Japan J. Appl. Phys. 21 L183–5. These developments have added further to the versatility of diamond. Two other groups of materials based on carbon, namely the fullerenes and graphines have been identified in recent years and are now the subject of intense research.

https://iopscience.iop.org/article/10.1088/0034-4885/75/12/126505/pdf

The mechanical and strength properties of diamond

The packaging of microelectromechanical systems (MEMS) and nanoscale devices constitutes an important area of research and development that is vital to the commercialization of such devices. Packaging needs of these devices include interfaces to nonelectronic domains; integration of structures, devices, and subsystems made with incompatible fabrication processes into a single platform; and the ability to handle a very large numbers of parts. Although serial, robotic assembly methods such as pick-and-place have allowed significant manufacturing feats, self-assembly is an attractive option to tackle packaging issues as the size of individual parts decreases below 300 /spl mu/m. In this paper, we review advances made in the usage of self-assembly for packaging and potential directions that growth in this area can assume. In the micrometer scale, we review the use of capillary forces, gravity, shape recognition, and electric fields to guide two- and three-dimensional self-assembly processes. In the nanoscale, we survey the usage of self-assembled molecular monolayers to solve current packaging issues, DNA hybridization for guiding self-assembly processes of nanoscale devices, and methods used to package nanowires or nanotubes into electronic circuits. We conclude with an example of a nanoscale biosensor which directly incorporates the concept of its package into its fabrication process. Even though the idea of a fully self-packaging system has not been demonstrated to date, the body of work reviewed and discussed here presents a solid foundation for the pursuit of this goal.

Self-assembly for microscale and nanoscale packaging: steps toward self-packaging

Chemical mechanical polishing of thin film diamond

In this research, we investigated the performance of polished chemical vapor deposited (CVD) diamond tool carbide inserts in comparison with unpolished CVD diamond coated carbide tool inserts in the dry turning of A390 aluminum–silicon hypereutectic alloy. The special emphasis is on exploring the role of machining parameters and cutting tool surface morphology on the aerosol generation. Global demand for high speed machining in combination with environmentally benign methods make diamond coated carbide tools an attractive candidate for dry machining. The results of this research demonstrate that CVD diamond-coated polished tools generate fewer particles, unlike conventional diamond tools (PCD and unpolished CVD), which cause the formation of respirable airborne particles during machining. Further, polished CVD diamond tool inserts improve tool life and reduce the cutting forces. Overall, in an important finding it is shown that polishing of tools provides a better opportunity for an environmentally benign dry machining along with improvement in machining outcome.

Dry machining of aluminum-silicon alloy using polished CVD diamond-coated cutting tools inserts

In this paper, an AlN/free-standing nanocrystalline diamond (NCD) system is proposed in order to process high frequency surface acoustic wave (SAW) resonators for sensing applications. The main problem of synthetic diamond is its high surface roughness that worsens the sputtered AlN quality and hence the device response. In order to study the feasibility of this structure, AlN films from 150 nm up to 1200 nm thick have been deposited on free-standing NCD. We have then analysed the influence of the AlN layer thickness on its crystal quality and device response. Optimized thin films of 300 nm have been used to fabricate of one-port SAW resonators operating in the 10–14 GHz frequency range. A SAW based sensor pressure with a sensibility of 0.33 MHz/bar has been fabricated.

/pdf/high-precision-pressure-sensors-based-on-saw-devices-in-the-4l5tmdcop6.pdf

High precision pressure sensors based on SAW devices in the GHz range

A review of techniques for polishing and planarizing chemically vapor-deposited (CVD) diamond films and substrates

Two challenges for interconnecting/interfacing MEMS devices to the real world are reliable signal transfer and media compatible material interfaces. For example, in electrical signal interconnection, poly-Si MEMS surfaces have a lubrication layer to reduce stiction and friction at physically static and dynamic interfaces, respectively. In this paper, we present the results of a study of wirebond and flip-chip interconnections on self-assembled monolayer (SAM) lubricated MEMS.

Effects of packaging process steps on the functionality of MEMS devices : Investigation of electrical interconnection on lubricated MEMS

Laser processing of materials in a liquid medium was examined in this study. A gold solution was used to coat gold onto aluminum, silicon, alumina, and diamond substrates using a 500 mW Ar ion laser and a 3.5 W Nd-YAG laser. The Ar ion laser was found suitable for gold reactive laser deposition. It was observed that the substrate electrical conductivity plays a dominant role in the deposition process. Substrates with a higher thermal conductivity required more laser power for deposition. Laser processing in a liquid medium was shown to be effective and could be used to fabricate electrode and interconnects.

The effects of substrate properties on metal coatings from liquid medium by reactive laser deposition

https://asmedigitalcollection.asme.org/IMECE/proceedings-pdf/doi/10.1115/IMECE2000-1903/6788894/959_1_imece2000-1903.pdf

B. S. Park

Papers

A review of techniques for polishing and planarizing chemically vapor-deposited (CVD) diamond films and substrates

Effects of packaging process steps on the functionality of MEMS devices : Investigation of electrical interconnection on lubricated MEMS

The effects of substrate properties on metal coatings from liquid medium by reactive laser deposition

Laser-Assisted Surface Engineering of Silicon Nitride to Minimize the Surface Defects Generated During Grinding Operation: Part I