High temperature rectifying contact

#This invention relates to semiconductor devices, and more particularly to a high temperature rectifying contact for semiconductor devices.

#Diamond is a preferred material for semiconductor devices because it has semiconductor properties that are better than traditionally used silicon (Si), germanium (Ge) or gallium arsenide (GaAs). Diamond provides a higher energy band gap, a higher breakdown voltage and a greater saturation velocity than these traditional semiconductor materials. These properties of diamond yield a substantial increase in projected cutoff frequency and maximum operating voltage compared to devices fabricated using Si, Ge, or GaAs. Si is typically not used at temperatures higher than about 200.degree. C. and GaAs is not typically used above 300.degree. C. These temperature limitations are caused, in part, because of the relatively small energy band gaps for Si (1.12 eV at ambient temperature) and GaAs (1.42 eV at ambient temperature). Diamond, in contrast, has a large band gap of 5.47 eV at ambient temperature, and is thermally stable up to about 1400.degree. C.

#Diamond has the highest thermal conductivity of any solid at room temperature and exhibits good thermal conductivity over a wide temperature range. The high thermal conductivity of diamond may be advantageously used to remove waste heat from an integrated circuit, particularly as integration densities increase. In addition, diamond has a smaller neutron cross-section which reduces its degradation in radioactive environments, i.e., diamond is a "radiation-hard" material.

#FIG. 1 is a cross-sectional side elevation view of a rectifying contact according to the present invention.

#FIG. 2 is a cross-sectional side elevational view of another embodiment of a rectifying contact according to the present invention.

#FIG. 3 is a scanning tunneling micrograph (STM) of a rectifying contact provided in accordance with Example 1.

#The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, Applicants provide these embodiments so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the thickness of layers and regions are exaggerated for clarity. Prime notation is used to indicate similar elements.

#Referring to FIG. 1, there is shown a rectifying contact according to the present invention designated by reference numeral 10. The contact 10 includes a monocrystalline semiconducting diamond layer 20 onto which is deposited a heteroepitaxial metal layer 30. In the embodiment illustrated in FIG. 1, the semiconducting monocrystalline diamond layer 20 is formed on a substrate 50. Exemplary substrates 50 may be silicon, diamond, sapphire, boron nitride, and the like.

#The monocrystalline diamond layer 20 may have a thickness of greater than about 100 .ANG., preferably between about 1 .ANG. and about 250 .mu.m, and most preferably about 1 .mu.m to about 250 .mu.m. The heteroepitaxial metal layer 30 may have a thickness of greater than about 20 .ANG. and between about 500 .ANG. and 1 .mu.m.