Polishing method for SOI
AssigneeNippondenso Co., Ltd.
InventorsMasaki Matsui, Masatake Nagaya, Akinari Fukaya, Hiroaki Himi
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Abstract
In a dielectric isolation substrate, an end point of a polishing process for selective polishing for forming an SOI layer is detected with a high precision. When polishing a wafer with a polishing pad, the temperature of a region of the polishing pad having polished the wafer at a position immediately thereafter is detected by a temperature sensor and the selective polishing process is ended by discriminating that the rate of variation in the detected temperature has changed from a positive to a negative state and then to a fixed saturated state.
Claims24
A method for polishing a material, said method comprising the steps of:
- providing a stopper material having at least one protruding portion extending through a portion of the material and towards a surface of the material, the stopper material being selected to have a polishing rate lower than a polishing rate of the material;
- polishing the surface of the material with a polishing pad constructed and arranged to make contact with the surface of the material;
- measuring a temperature of the polishing pad at different times during said polishing step to obtain a plurality of measured temperatures;
- and
- detecting an end point of said polishing step based on variations of the measured temperatures.
A method for polishing a semiconductor substrate to a prescribed thickness with a polishing pad, said method comprising the steps of:
- rotating a turntable having the polishing pad disposed on a surface thereof at a prescribed speed;
- polishing a surface of the semiconductor substrate, said polishing step comprising rotating a chuck table with the semiconductor substrate fixed thereto at a prescribed speed, swinging the chuck table relative to the turntable so as to follow a swinging motion, and pressing the surface of the semiconductor substrate against the polishing pad;
- detecting in a non-contact manner a temperature of the polishing pad with a temperature sensor at a position where a portion of the polishing pad passes through immediately after the portion has polished the surface of the semiconductor substrate, said detecting step being conducted at different times during said polishing step to obtain a plurality of measured temperatures, the temperature sensor being located on the chuck table and swinging jointly with the swing motion of the chuck table;
- and
- determining an end point of said polishing step based on variations of the measured temperatures.
A method for polishing an insulator film deposited on a semiconductor substrate, said method comprising the steps of:
- polishing a surface of the insulator film with a polishing pad to a plane along which recessed portions and protruding portions of the insulator film are arranged;
- measuring a temperature of the polishing pad at a position where a portion of the polishing pad passes through immediately after the portion has polished the surface of the insulator film, said measuring step being conducted at different times during said polishing step to obtain measured temperatures;
- and
- detecting an end point of said polishing step based on variations of the measured temperatures.
A method of polishing a material with a polishing pad, said method comprising the steps of:
- mounting the polishing pad on a turntable and polishing the material
- adjusting a temperature of the turntable during said polishing step so that the temperature of the. turntable becomes fixed;
- and
- detecting an end point of the polishing step by detecting a saturated state of an amount of heat generated during said polishing step.
A method for polishing a material with a polishing pad, comprising the steps of:
- polishing the material, during which a total amount of heat is generated due to said polishing, the total amount of heat being based on the temperature of the polishing pad and a time duration of said polishing step;
- measuring a temperature of the polishing pad during said polishing step;
- detecting an end point of said polishing step based on a relationship between the total amount of heat generated due to said polishing step and a volume of the material which is removed by the polishing pad during said polishing step.
A method for manufacturing a semiconductor substrate, said method comprising the steps of:
- providing a substrate comprising first and second semiconductor substrates with an insulator film interposed therebetween, the insulator film having a configuration defined by recesses and protrusions and a polishing rate that is lower than a polishing rate of the first semiconductor substrate;
- selectively polishing the first semiconductor substrate with a polishing pad from a surface of the first semiconductor film until the protrusions of the insulator film are exposed such that the insulator film functions as.a stopper;
- measuring a temperature of the polishing pad at a position where a portion of the polishing pad passes after the portion has polished the surface of the first semiconductor substrate, said measuring step being conducted at different times during said polishing step to obtain measured temperatures;
- and
- detecting an end point of said polishing step based on variations of the measured temperatures.
A method for manufacturing a semiconductor substrate, said method comprising the steps of:
- providing a substrate comprising first and second semiconductor substrates with an insulator film interposed therebetween, the insulator film having a configuration defined by recesses and protrusions and a polishing rate that is lower than a polishing rate of the first semiconductor substrate;
- selectively polishing the first semiconductor substrate with a polishing pad from a surface of the first semiconductor film until the protrusions of the insulator film are exposed such that the insulator film functions as a stopper;
- forming a semiconductor device in the first semiconductor substrate in one of the recesses of the, insulator film;
- measuring a temperature of the polishing pad at a position where a portion of the polishing pad passes after the portion has polished the surface of the first semiconductor substrate, said measuring step being conducted at different times during said polishing step to obtain measured temperatures;
- and
- detecting an end point of said polishing step based on variations of the measured temperatures.
Dependencies are inferred from the claim text.