Parametric profiling using optical spectroscopic systems to adjust processing parameter

• US 20060132806A1
• Filed: 01/30/2006
• Published: 06/22/2006
• Est. Priority Date: 12/19/2000
• Status: Active Grant

• Current Assignee: Anatoly Fabrikant, Andrei V. Shchegrov, Mehrdad Nikoonahad
• Original Assignee: Anatoly Fabrikant, Andrei V. Shchegrov, Mehrdad Nikoonahad
• Inventors: Fabrikant, Anatoly, Nikoonahad, Mehrdad, Shchegrov, Andrei V.
• Granted Patent: US 7,312,881 B2
• Time in Patent Office: Days
• US Class Current: 356/625
• CPC Class Codes: G01J 3/447 Polarisation spectrometry
• CPC Class Codes: G01J 4/04 Polarimeters using electric detection means G01J4/02 takes precedence
• CPC Class Codes: G01N 21/211 Ellipsometry optical thickness measurement G01B11/06
• CPC Class Codes: H01L 22/20 Sequence of activities consisting of a plurality of measurements, corrections, marking or sorting steps

Abstract

A gallery of seed profiles is constructed and the initial parameter values associated with the profiles are selected using manufacturing process knowledge of semiconductor devices. Manufacturing process knowledge may also be used to select the best seed profile and the best set of initial parameter values as the starting point of an optimization process whereby data associated with parameter values of the profile predicted by a model is compared to measured data in order to arrive at values of the parameters. Film layers over or under the periodic structure may also be taken into account. Different radiation parameters such as the reflectivities R_s, R_p and ellipsometric parameters may be used in measuring the diffracting structures and the associated films. Some of the radiation parameters may be more sensitive to a change in the parameter value of the profile or of the films then other radiation parameters. One or more radiation parameters that are more sensitive to such changes may be selected in the above-described optimization process to arrive at a more accurate measurement. The above-described techniques may be supplied to a track/stepper and etcher to control the lithographic and etching processes in order to compensate for any errors in the profile parameters.

Claims

1. An integrated processing and detection apparatus for processing a sample having structures thereon, comprising:

a system that finds a profile of a structure having a dimension in the micron or submicron range and fabricated by a process, wherein the system measures the structure by directing a polychromatic beam of electromagnetic radiation at said structure, detects corresponding radiation data from said beam after it has been modified by the structure at a number of wavelengths from said structure and analyzes the data to provide information related to the structures; and

a processing system processing the sample in response to said information for adjusting a processing parameter.

2. The apparatus of claim 1, said system providing a gallery of a plurality of profile types, each profile type associated with a set of one or more parameters and a set of radiation data, wherein at least one of said profile types provided is associated with a plurality of sets of radiation data of different radiation parameters, said radiation parameters including reflectance or transmittance parameters and ellipsometric parameters;

wherein said system;

selects a profile type from the gallery; and

selects at least one set of radiation data from the sets of radiation data of different parameters associated with the selected profile type based on sensitivity of such data to a change in the one or more parameters;

wherein said analyzing includes comparing the detected parameters to the set selected to arrive at a set of value(s) of the one or more parameters.

3. The apparatus of claim 2, wherein at least one of said profile types in the gallery provided includes a periodic structure on and/or below one or more layers of material, and the sets of data include one set corresponding to said at least one of said profile types and the one or more layers.

4. The apparatus of claim 3, said processor selecting a radiation parameter and one or more sets of radiation data based on sensitivity of such data to a change in the one or more parameters of the profile type, and a change in a characteristic of the one or more layers.

5. The apparatus of claim 3, wherein said one or more parameters include one or more of the following:

width, height and sidewall angle, thickness and index of refraction.