Optical end point detection methods in semiconductor planarizing polishing processes

A semiconductor processing method of detecting polishing end point in a chemical-mechanical polishing planarization process comprising the following sequential steps:

• a) chemical-mechanical polishing an outermost surface of a semiconductor substrate using a chemical-mechanical polishing pad;
• b) during such chemical-mechanical polishing, impinging laser light onto an area of the outermost surface of the semiconductor substrate at an angle of incidence of at least 75.degree. from a line normal relative to the substrate, the impinged laser light predominantly reflecting off the area as opposed to transmitting therethrough;
• c) during such chemical-mechanical polishing, measuring intensity of the step "b" light reflected off of the area;
• d) repeating step "b" then step "c";
• and
• e) detecting a change in a later measured intensity of reflected light as compared to an earlier measured intensity of reflected light as the surface being chemical-mechanical polished becomes substantially planar;
• and
• f) ceasing chemical-mechanical polishing upon detection of the change;
• and
• the method further comprising reflecting the reflected light back onto the substrate outermost surface at the angle of incidence multiple times with a mirror, and wherein step "c" comprises measuring the intensity of the multiple reflected light.

A semiconductor processing method of detecting polishing end point from a polishing planarization process, the method comprising the following sequential steps:

• a) impinging s-polarized laser light onto an area of an outermost surface of a semiconductor substrate at an angle of incidence of at least 60.degree. from a line normal relative to the substrate, the impinged s-polarized laser light predominantly reflecting off the area as opposed to transmitting therethrough;
• b) measuring intensity .of the step "a" s-polarized light reflected off the area;
• c) polishing the substrate outermost surface;
• d) repeating step "a" then step "b";
• and
• e) comparing a prior measured intensity of s-polarized reflected light with a later measured intensity of s-polarized reflected light to determine a change in degree of planarity of the semiconductor substrate outermost surface as a result of polishing;
• and
• f) the method further comprising reflecting the reflected light back onto the substrate outermost surface at the angle of incidence multiple times with a mirror, and wherein step "b" comprises measuring the intensity of the multiple reflected light.

A semiconductor processing method of detecting polishing end point in a chemical-mechanical polishing planarization process comprising the following sequential steps:

• a) chemical-mechanical polishing an outermost surface of a semiconductor substrate using a chemical-mechanical polishing pad;
• b) during such chemical-mechanical polishing, impinging s-polarized laser light onto an area of the outermost surface of the semiconductor substrate at an angle of incidence of at least 60.degree. from a line normal relative to the substrate, the impinged laser light predominantly reflecting off the area as opposed to transmitting therethrough;
• c) during such chemical-mechanical polishing, measuring intensity of the step "b" s-polarized light reflected off of the area;
• d) repeating step "b" then step "c";
• and
• e) detecting a change in a later measured intensity of s-polarized reflected light as compared to an earlier measured intensity of s-polarized reflected light as the surface being chemical-mechanical polished becomes substantially planar;
• and
• f) ceasing chemical-mechanical polishing upon detection of the change;
• and the method further comprising reflecting the reflected light back onto the substrate outermost surface at the angle of incidence multiple times with a mirror, and wherein step "c" comprises measuring the intensity of the multiple reflected light.