Abstract: A method of fault classification in a plasma process chamber powered by an RF source includes initially running a plurality of different baseline plasma processes on the chamber. For each baseline process, the magnitudes of a plurality of Fourier components of delivered RF power are determined and stored as an impedance fingerprint for that baseline process. In the case of a fault, one or more of the baseline processes is repeated according to a predetermined decision tree to determine the current fingerprints and classify the fault by comparing the current fingerprints with the original fingerprints.

Abstract: In a method of manufacturing a miniature multilayer device 10 a low open area dielectric layer 18 is selectively etched through to an underlying conductive region 16 using an electrically conducting medium such as a plasma 24. The endpoint of the etch process is determined by detecting the abrupt change in capacitance across the device 10 just as the final portion of the dielectric layer is removed.

Abstract: A method of fault classification in a plasma process chamber powered by an RF source comprises initially running a plurality of different baseline plasma processes on the chamber. For each baseline process, the magnitudes of a plurality of Fourier components of delivered RF power are determined and stored as an impedance fingerprint for that baseline process. In the case of a fault, one or more of the baseline processes is repeated according to a predetermined decision tree to determine the current fingerprints and classify the fault by comparing the current fingerprints with the original fingerprints.

Abstract: A sensor for detecting RF current flowing in a conductor includes a layer 10 of insulating material with a hole 16 for the passage of the RF conductor 18 in a direction normal to the layer. A plurality of conductive tracks 20, 22 (FIG. 3) on the opposite major surfaces of the layer are selectively joined by a plurality of through-holes each containing conductive material. The conductive material selectively connects the conductive elements 20, 22 to form a plurality of loops (FIG. 4) disposed non-parallel to the layer 10 for inductive coupling to the RF conductor 18.

Abstract: A method of processing a high frequency signal containing at least two different fundamental frequencies F1 and F2 and their harmonic components in order to extract at least one harmonic component of each of the two fundamental frequencies comprises sampling the signal at two sampling frequencies CK1=F1(M1/N1) and CK2=F2(M2/N2), where M1 and N1 are a first pair of integers having no common factor and M2 and N2 are a second pair of integers having no common factor. The sample values resulting from sampling at CK1 are stored cyclically in a set of M1 memory locations such that the nth sample value is stored cumulatively in the remM1[n]th memory location, and the sampled values resulting from sampling at CK2 are stored cyclically in a set of M2 memory locations such that the nth sample value is stored cumulatively in the remM2[n]th memory location.

Abstract: In a method of manufacturing a miniature multilayer device 10 a low open area dielectric layer 18 is selectively etched through to an underlying conductive region 16 using an electrically conducting medium such as a plasma 24. The endpoint of the etch process is determined by detecting the abrupt change in capacitance across the device 10 just as the final portion of the dielectric layer is removed.