Substrate inspection using the propagation characteristics of RF electromagnetic waves

A substrate inspection device, comprising:

• a standard substrate of good quality and of a structure symmetrical to that of a sample substrate to be inspected;
• a first electrode plate arranged on an obverse surface of said standard substrate;
• a second electrode plate arranged in a space between a reverse surface of said standard substrate and an obverse surface of said sample substrate;
• a third electrode plate arranged on a reverse surface of said sample substrate;
• a network analyzer for measuring propagation characteristics of radio frequency (RF) electromagnetic waves from said second electrode plate to said first electrode plate as standard characteristics and the propagation characteristics of RF electromagnetic waves from said second electrode plate to said third electrode plate as test characteristics;
• and
• a quality judging means for comparing the test characteristics with the measured standard characteristics to determine whether said sample substrate is good or bad,
• wherein a central portion of said second electrode plate where said standard substrate and said sample substrate are to be arranged is formed in a reticulated form, and
• an outer edge portion of said second electrode plate to be connected to said network analyzer is divided into a plurality of portions.

A substrate inspection method, comprising the steps of:

• preparing a standard substrate of good quality and of a structure symmetrical to that of a sample substrate to be inspected;
• arranging said standard substrate and said sample substrate in symmetrical opposition with a flat electrode member interposed therebetween;
• causing radio frequency (RF) electromagnetic waves to propagate in said electrode member that confronts said standard substrate on its obverse side and said sample substrate on its reverse side and measuring characteristics of RF electromagnetic waves by a network analyzer;
• determining whether or not defects exist on a surface of said sample substrate based on results of said characteristics;
• and
• preparing, as said electrode member, a component having a multiplicity of linear electrode wires arranged in parallel with each other in a planer form,
• wherein said step of propagating RF electromagnetic waves in said electrode member and measuring characteristics includes the steps of:
• applying RF electromagnetic waves, via said network analyzer, to either odd-numbered or even-numbered electrode wires of said multiplicity of electrode wires;
• and
• measuring RF electromagnetic waves generated in the other of either the odd-numbered electrode wires or even-numbered electrode wires of said multiplicity of electrode wires.

A substrate inspection method, comprising the steps of:

• preparing a standard substrate of good quality and of a structure symmetrical to that of a sample substrate to be inspected;
• arranging a first electrode plate, said standard substrate, a second electrode plate, said sample substrate, and a third electrode plate, in that order, with the standard substrate and said sample substrate facing symmetrically with each other;
• measuring, via a network analyzer, both the propagation characteristics of radio frequency (RF) electromagnetic waves from said second electrode plate to said first electrode plate as standard characteristics and the propagation characteristics of RF electromagnetic waves from said second electrode plate to said third electrode plate as test characteristics;
• and
• comparing the test characteristics with the measured standard characteristics to determine whether said sample substrate is good or bad.

A substrate inspection device, comprising:

• a standard substrate of good quality and of a structure symmetrical to that of a sample substrate to be inspected;
• a first electrode plate arranged on an obverse surface of said standard substrate;
• a second electrode plate arranged in a space between a reverse surface of said standard substrate and an obverse surface of said sample substrate;
• a third electrode plate arranged on a reverse surface of said sample substrate;
• a network analyzer for measuring propagation characteristics of radio frequency (RF) electromagnetic waves from said second electrode plate to said first electrode plate as standard characteristics and the propagation characteristics of RF electromagnetic waves from said second electrode plate to said third electrode plate as test characteristics;
• and
• a quality judging means for comparing the test characteristics with the measured standard characteristics to determine whether said sample substrate is good or bad.

A substrate inspection method, comprising the steps of:

• preparing a standard substrate of good quality and of a structure symmetrical to that of a sample substrate to be inspected;
• arranging said standard substrate and said sample substrate in symmetrical opposition with a flat electrode member interposed therebetween;
• causing radio frequency (RF) electromagnetic waves to propagate in said electrode member that confronts said standard substrate on its obverse side and said sample substrate on its reverse side;
• separately receiving RF electromagnetic waves propagated from the electrode member through the standard substrate on a side thereof opposite to the obverse side and through the sample substrate on a side thereof opposite to the reverse side;
• measuring characteristics of the separately received RF electromagnetic waves;
• and
• determining whether or not defects exist on a surface of said sample substrate based on the results of said measuring step.