lithoAPC Modules

lithoAPC Run to Run

Features

lithoAPC impresses with its modern design and user friendly user interface. The user can navigate between all features easily since the well structured architecture.

Comfortable user interface

All modules are integrated into the APC desktop application. The user interface combines all functionality to setup, monitor and control the APC control. In details this covers:

visualize measurement and process data
create, delete and setup all master data
control status of master data
visualize and compare all analysis results and intermediate information including
- systematic failure
- value and residual statistics
- residuals
trigger manual analysis for single or selected runs
edit run context information or measurement values
access wafer visualizations
visualize the process time line in diagrams
access user management and system capabilities
connect to any lithoAPC server in the network
export and import functionality
copy of all table information

The ongoing development of the system will produce frequent new modules and new features accessible in the user interface.

Screenshot RuntoRun View

Master data and parametrization

lithoAPC is completely configurable via master data. Any master data item can be an instruction or some piece of information, which is required for the analysis like wafer layout, target set, parameter model.
New master data implementations but also customer’s master databases are accepted and enable functional extensions of the system.
Master data can be parametrized. Such parameters are evaluated dynamically during the analysis. In this case the values are evaluated at the first request for the given run.

LVHM production support

LVHM (Low Volume – High Mix) FABs have special requirements. lithoAPC is focusing on those needs to provide best performance for production and optimal user experience for the engineers.

Optimal througput

The focus of lithoAPC is on high prediction quality of the offset values and exposure settings for the process tool. Based on modern filter technologies, lithoAPC selects the optimal set of former exposures to calculate best offset values and exposure energy.
Especially in logic FABs (LVHM) pilot wafers are needed for product ramp up and after tool maintenance. lithoAPC address the pilot wafer use cases and provides approaches to avoid or to reduce the need of pilot wafers.

Real time support

lithoAPC always uses actual data. Some predictions of startup values analyse data for 6 month and more. The time for calculation new starting values is critical because it is tool time. lithoAPC provides all data within the shortest time possible (98%: <1s; 2%<3s).

Configurable R2R controller

The integrated R2R Controller is a complex and configurable controller. It already supports all common photo lithography use cases. With this control, even the most demanding applications of the exposure process in terms of R2R configuration and start value generation become simple

Extendible and modular system architecture

lithoAPC is expandable. All features are implemented based on a modular architecture and are dynamically bind during run time. New features can be easily integrated into the system – independent, whether they are provided by BlueLine AG, the IT department of the FAB or any 3rd party.

Advanced merge approach

Incoming data is automatically merged with existing process information for the same lot and layer. The merge algorithm recognizes the correct sequence of exposures and measurements. Even complex use cases like tool aborts, reworks and splits are handled by the software.

Default values

Standard prediction

lithoAPC allows to calculate starting values for the process tool. This calculation is based on reference runs with similar process conditions. The standard case greps a specific number of reference runs. Based on these runs, a R2R controller calculates the optimum starting parameters using the configured controller. By default an EWMA controller is used (enhanced weighted moving average). This controller can be replaced with other approaches.
The system allows to run several controllers in parallel. Each controller will manage a predefined subset of all starting parameters. This offers the greatest flexibility for all applications in photo lithography.

User definable R2R levels with fall back

The system can be setup using R2R levels. With this approach, the entire process can be described from a R2R perspective. Especially for high mix production lines and tool mix without dedication, the R2R level support groups e.g. for similar tools or products. This apporach has proven itself in many advanced logic FABs over years. The use of R2R levels provides full access to all filter functions like

flexible selection of filter criteria
dynamic filter criteria (dynamically
evaluated
based on customer sources)
virtual grouping
grouping by target or gradient values

Selectable optimization strategy (default: EWMA)

The selected historical runs are optimized with an assigned optimizer. By default, EWMA is being used, but the user can replace it with any other optimizer.

Control flow using UseApc flag

The R2R functionality is enabled by default and can be disabled for selected processes. If APC is disabled the default values are being used.

Virtual grouping

There are logic products, which are identical up to a certain process layer. Technically those products fit into the same controller group – but due to different product names these products often are handled completely independent of each other. To avoid pilot wafers runs and in order to learn from the other products within the group, lithoAPC enables the declaration of virtual product groups.

Unique 2-phase streaming data filter

The common database filtering method is applied on database level. In addition a second filter is applied on system level, which takes care for all sophisticated filter criteria like dynamic context information. To ensure fastest response times a life stream to the database is used for filters, flier checks and validations. The filter supports complex criteria based on the current run context as well on any context information in the MES system. It includes the status information, scope of time and more. Without any additional effort, the user can filter – for example – by reference layer information or a process tool.

Flier elimination

The calculation of the startup values is based on previous runs and their optimal process conditions. The system expects a continuous distribution and tests the data quality. The flier elimination will detect and remove all runs, which do not follow the common behavior. Flier elimination is based on a combination of absolute flier limits and the definition of relative tunnels.

Constraint check on start-up data

The reference data should follow a predefined minimum quality. This quality level is defined based on rules. In case of any violation of the user-defined data range the software allows to trigger a pilot wafer to validate the process.

Use constraints

The reference data should follow a predefined minimum quality. This quality level is defined based on rules. In case of any violation, which can be used to trigger a pilot wafer.

Full inline support for any tool and tool type combinations

The system distinguishes between different tool types. Logical controller groups are supported. Logical controllers can combine data or allows to split data into distinct groups.

Included graphical user interface with easy access to all data and each detail of the controller setup

The extendible user interface allows easy access to all data from any client. The platform approach supports the seamless integration of new modules.

Full traceability of all data including controller setup

The system stores all exposure and measurement activities – no data is lost. lithoAPC will assign the correct measurement to the appropriate exposure entry. Aborted exposures and re-measurements are still stored in the database and provide a complete, unfiltered view of the activities in photo lithography. The existing complete time line allows to simulate the process with changed process setup for any time frame in the past.

Reset management

Some process issues require to disable selected runs. Such runs are never used for any calculation. But these runs are still stored and visible in the user interface.

Charting

All diagramming is based on a separate module called “Statistics module”. It allows to define diagram templates for various visualization types and to combine those with analysis and R2R data. Finally, the templates can be called from the analysis or R2R modules to visualize the currently selected runs.

This template approach is a very efficient and flexible. It supports advanced diagramming features like:

various diagramming types
scatter plot
box plot
pie charts
bar plot
probability plot
table output
event time line
histogram and normal
distribution chart

In addition the data can be group into distinct charts or series based on the run context.

Gradient monitor

lithoAPC provides capabilities to monitor and upgrade the gradient information. This includes comparing runs from different processes and their behavior and finding similarities and differences. The effort for test runs to update the gradient can be reduced and the production quality can be increased.

Integrated baseline correction

The integrated baseline correction is an advanced feature. Process parameters are not only subject of process behavior. There are also dependencies on the substrate, maintenance activities, resist batches or mask size. Often the impact is just an offset (bias) to the initial baseline. lithoAPC allows to specify such baseline offsets. With this information all available data can be used to predict new starting values even if the data are at different baseline levels. There is no need to delete any data and there is no need to run additional any pilot wafers.

Best matching view

Different master data are implemented as look-up tables and allow the definition of parameters.
The parameters are each assigned to a set of context values that correspond to the respective processes.
The “Best Matching View” provides a quick overview of the lockup tables and the parameters for a specific run.

Source Code Option

Every APC solution is a critical part of semiconductor production. This concerns both the availability of the APC solution and the support for new requirements. We offer a source-code option for the APC solution, which allows you to integrate your own modules, implement new functions and, if required, continue to develop the solution independently.

lithoAPC Critical Dimension

Features

lithoAPC impresses with its modern design and user friendly user interface.
The user can navigate between all features easily since the well structured architecture.