Coating device and coating method

#The invention relates to a coating device, comprising at least one evacuable recipient which is intended for receiving a substrate, at least one gas supply device, by means of which at least one gaseous precursor can be introduced into the recipient, and at least one activation device which comprises at least one heatable activation element, the end of which is fastened to a holding element at a fastening point, wherein a shielding element is present, by means of which at least the fastening point can be protected at least partially against the action of the gaseous precursor, the shielding element being of essentially cylindrical design, and there being arranged on that side of the shielding element which faces away from the holding element a closing element which has at least one outlet port. The invention relates, furthermore, to a corresponding coating method.

#Coating devices of the type mentioned are intended, according to the prior art, for coating a substrate by means of hot wire-activated chemical vapor deposition. The deposited layers may comprise, for example, carbon, silicon or germanium. The gaseous precursors may correspondingly comprise, for example, methane, silicon tetrahydride, monogermanium, ammonia or trimethyl silane.

#It is known from P. A. Frigeri et al.: “Hot Wire Chemical Vapour Deposition: Limits and Opportunities of protecting the tungsten catalyzer from silizide with a cavity”, Thin Solid Films Vol. 517, Iss. 12 (2009) 3427, that an undesirable reaction of the material of the activation element with the precursor takes place particularly at the relatively cold clamping points of the activation element. For example, the use of a silane compound as precursor may lead to the formation of silicide phases on the activation element. These silicide phases modify the electrical resistance, the surface quality and the mechanical load-bearing capacity of the activation element, and therefore, this often has to be exchanged after only brief use.

#The invention will be explained in more detail below by means of exemplary embodiments and figures, without the general idea of the invention being restricted. In the figures:

#FIG. 1 shows the basic set-up of a coating device according to the invention.

#FIG. 2 illustrates one possible embodiment of the shielding element proposed according to the invention.

#FIG. 1 shows a cross section through a coating device 1. The coating device 1 comprises a recipient 10 which is produced, for example, from high-grade steel, aluminum, glass or a combination of these materials. The recipient 10 is closed off, essentially air-tight, with respect to the surroundings. A vacuum pump, not illustrated, may be connected via a pump flange 103. For example, the recipient 10 may be evacuated to a pressure of less than 100 mbar, of less than 10−2 mbar or of less than 10−6 mbar.

#Located inside the recipient 10 is a holding device 104 on which a substrate 30 can be held. The substrate 30 may be composed, for example, of gas, silicon, plastic, ceramic, metal or an alloy. For example, the substrate may be a semiconductor wafer, a disk or a tool. It may have a planar or curved surface. Said materials are in this case mentioned merely by way of example. The invention does not teach the use of a specific substrate as a principle of the solution. When the coating device 1 is in operation, a coating 105 is deposited on the substrate 30.

#The composition of the coating 105 is influenced by the choice of the gaseous precursor. In one embodiment of the invention, the precursor may comprise methane, so that the coating 105 comprises diamond or diamond-like carbon. In another embodiment of the invention, the precursor may comprise silicon tetrahydride and/or monogermanium, so that the coating comprises crystalline or amorphous silicon and/or germanium.