Lam Research Corporation

Tencor Instruments

Jiri Pecen

Wilbur C Krusell

Rahul Jairath

Saket Chadda

Rajeev Bajaj

George J Kren

Erik H Engdahl

Herbert Elliot Litvak

Stephen C Jew

Jerauld J Cutini

Rahul K Surana

Armand P Neukermans

Kenneth P Gross

Brian C Leslie

Lee K Galbraith

Lloyd J LaComb, Jr

John Fielden

Soheil Saadat

An apparatus and method for in-situ monitoring of thickness during chemical-mechanical polishing (CMP) of a substrate using a polishing tool and a film thickness monitor. The tool has an opening placed in it. The opening contains a monitoring window secured in it to create a monitoring channel. A film thickness monitor (comprising an ellipsometer, a beam profile reflectometer, or a stress pulse analyzer) views the substrate through the monitoring channel to provide an indication of the thickness of a film carried by the substrate. This information can be used to determine the end point of the CMP process, determine removal rate at any given circumference of a substrate, determine average removal rate across a substrate surface, determine removal rate variation across a substrate surface, and optimize removal rate and uniformity.

Method and apparatus for in-situ monitoring of thickness during chemical-mechanical polishing

A linear polishing belt for use in chemical-mechanical polishing (CMP) of a substrate comprises an opening and a flexible monitoring window secured to the belt to close the opening and to create a monitoring channel in the belt. A plurality of monitoring channels can also be used. A film thickness monitor comprising an interferometer can be disposed alongside the belt or at least partially within a region bound by it. The monitoring channel and the film thickness monitor can be used in the CMP process to determine the end point of the CMP process, determine removal rate at any given circumference of a substrate, determine average removal rate across a substrate surface, determine removal rate variation across a substrate surface, and optimize removal rate and uniformity.

Method and apparatus for in-situ end-point detection and optimization of a chemical-mechanical polishing process using a linear polisher

A wafer polishing device with movable window can be used for in-situ monitoring of a wafer during CMP processing. During most of the CMP operation, the window remains below a polishing surface of a polishing device to protect the window from the deleterious effects of the polishing process. When the window moves into position between the wafer and a measurement sensor, the window is moved closer to the polishing surface. In this position, at least some polishing agent collected in the recess above the window is removed, and an in-situ measurement can be taken with reduced interference from the polishing agent. After the window is positioned away from the wafer and measurement sensor, the window moves farther away from the wafer and polishing surface. With such a movable window, the limitations of current polishing devices are overcome.

Wafer polishing device with movable window

Method and apparatus for in-situ end-point detection and optimization of

A method and apparatus for in-situ monitoring of thickness using a multi-wavelength spectrometer during chemical mechanical polishing (CMP) of a substrate using a polishing tool and a film thickness monitor. The tool has an opening placed in it. The opening contains a monitoring window secured in it to create a monitoring channel. A film thickness monitor views the substrate through the monitoring channel to provide an indication of the thickness of a film carried by the substrate. This information can be used to determine the end point of the CMP process, determine removal rate at any given circumference of a substrate, determine average removal rate across a substrate surface, determine removal rate variation across a substrate surface, and optimize removal rate and uniformity. The film thickness monitor comprises a spectrometer.

Method and apparatus for in-situ monitoring of thickness using a

Method and apparatus for in-situ monitoring of thickness during

A particle imager and method for imaging particles on surfaces of substrates. A surface is raster scanned by a collimated light beam and particles on the surface are detected by the scattered light caused by the particles. During a scan path the intensity of the scattered light is measured forming intensity traces and location addresses for the detected particles. Data from each scan path is stored in memory. The imager is pre-calibrated with a test wafer having light scattering marker points spaced at known positions thereon. Scanning the test wafer, a clock measures time elapsed from a start position to each marker point. The corresponding elapsed times and known address locations are stored in memory for reference during data collection.

Position location in surface scanning using interval timing between scan

A particle detection method for matching particles detected in two scans of a surface taken at different times in which particles having a light scattering intensity above a collection threshold are first detected and the measured position and scattering intensity therefor stored in a computer memory. Corresponding first and second measured positions from the respective first and second scans are determined by forming a triangle from selected first detected particles and finding those second detected particles which form a variant triangle with matching perimeter and area. From these matching first and second particles a transformation is found for mapping first measured positions to corresponding second positions and vice versa. Areas around corresponding positions of particles having a scattering intensity above a display threshold are examined for matching particles. If not found, the area is reexamined at a reduced threshold. Matching particles are considered to be the same, while unmatched particles are considered to be either added or removed. The method provides an accurate count of particles for process contamination analysis.

Particle detection method including comparison between sequential scans

A method and apparatus for particle detection and position correlation that fuses separate detections of the same particle on adjacent scan lines into one. A first scan line on a surface is scanned with a laser beam and the scattered light detected. The detection generates address and amplitude data for each particle which is stored. The second line scanned also generates data which is stored in a buffer. Particle data between scan lines is compared. Data for new particles is stored, data for previous particles no longer detected being sent to computer storage, and data for the same particle being compared and only the one with larger amplitude being kept. The results in computer storage may be displayed as a wafer with those pixels lit which have particles.

Particle position correlator and correlation method for a surface scanner

A test device for calibrating an optical scanner wherein microscopic patterns of light scattering elements simulate the scattering of light from particles or flaws of different sizes. Simulation of different particles sizes is achieved by means of clusters or arrays of these light scattering elements having different areawise densities. Patterns of such clusters or arrays are disposed on a surface with intervening spaces where a random assortment of foreign particles may be expected. In this manner, the foreign particles may be directly compared to a test pattern. The test surface may be a semiconductor wafer having a thin, inert coating with openings therein forming the light scattering elements. The openings may be made by photolithographic techniques, i.e., masking and etching, so that various patterns on a surface may be all created simultaneously by the same process.

Growing community of inventors

Palo Alto, CA, United States of America

Jiri Pecen