Process and metrology control, process indicators and root cause analysis tools based on landscape information
Methods and metrology modules are provided, which derive landscape information (expressing relation(s) between metrology metric(s) and measurement parameters) from produced wafers, identifying therein indications for production process changes, and modify production process parameters with respect to the identified indications, to maintain the production process within specified requirements. Process changes may be detected in wafer(s), wafer lot(s) and batches, and the information may be used to detect root causes for the changes with respect to production tools and steps and to indicate tool aging and required maintenance. The information and its analysis may further be used to optimize the working point parameters, to optimizing designs of devices and/or targets and/or to train corresponding algorithms to perform the identifying, e.g., using training wafers.
1. A method comprising:
deriving landscape information from produced wafers, wherein the landscape information comprises wavelength spectra signatures over the wafers, wherein the landscape information is carried out with respect to a plurality of wafers, wafer lots and/or batches, and wherein the landscape information is carried out with respect to a plurality of chambers,
identifying, in the derived landscape information, indications for production process changes, and
modifying production process parameters with respect to the identified indications, to maintain the production process within specified requirements,
wherein the landscape information comprises a visualization of a relation between at least one metrology metric and at least one recipe or measurement parameter with the wavelength spectra signatures at a field level and at a wafer level that track performance degradation with respect to a production tool of a plurality of production tools, wherein the production tool has one of the chambers, and
wherein at least one of the deriving, the identifying and the modifying is carried out by at least one computer processor.
2. The method of claim 1 , wherein the landscape information comprises at least one wafer map of landscapes which are spatially associated with the produced wafers.
3. The method of claim 1 , further comprising performing root cause analysis for the identified production process changes with respect to the production tools and/or the chambers.
4. The method of claim 1 , further comprising optimizing working point parameters, which comprise values of the recipe or measurement parameters, using zonal analysis relating to a spatial distribution of the landscape information across the wafers.
5. The method of claim 1 , further comprising training a corresponding algorithm to perform the identifying, using training wafers to which the method is applied.
6. The method of claim 1 , further comprising indicating tool aging and required maintenance, using the identified indications.
7. The method of claim 1 , further comprising optimizing designs of devices and/or targets with respect to the derived landscape information.
8. A metrology module configured to carry out the method of claim 1 .
9. A computer program product comprising a non-transitory computer readable storage medium having computer readable program embodied therewith, the computer readable program configured to carry out the method of claim 1 .
10. The method of claim 1 , wherein the identifying includes quantifying an amount of process change using machine learning.
11. The method of claim 1 , wherein modifying the production process parameters is part of a control loop for the production process parameters.
12. The method of claim 1 , wherein at least two of the chambers are in different production tools.
13. The method of claim 12 , wherein each of the production tools is an imaging metrology tool, a scatterometry metrology tool, a scanning electron microscopy tool, or an electron beam tool.