How can you optimize your fabrication process to improve yield?

1 Design for manufacturability

One of the first steps to optimize your fabrication process is to design your devices with manufacturability in mind. This means that you should consider the limitations and capabilities of the fabrication technology, the materials, and the equipment that you will use, and avoid features that are too complex, too small, or too sensitive to variations. For example, you should avoid sharp corners, narrow gaps, thin wires, or high aspect ratios that can cause defects, stress, or parasitic effects. You should also use standard cells, libraries, and design rules that are compatible with your fabrication technology and that have been verified and tested.

2 Choose the right materials

Another key factor that affects your fabrication process is the choice of materials. You should select materials that have the desired properties, such as conductivity, resistivity, permittivity, or refractive index, for your devices, but also that are compatible with the fabrication technology, the equipment, and the environment. For example, you should avoid materials that have high thermal expansion coefficients, high moisture absorption rates, or high susceptibility to oxidation or corrosion, as they can cause cracks, delamination, or degradation. You should also use materials that have low defect densities, low impurity levels, or low stress levels, as they can improve the performance and reliability of your devices.

3 Calibrate and maintain your equipment

The equipment that you use for fabrication can also have a significant impact on your yield and reliability. You should calibrate and maintain your equipment regularly, following the manufacturer's instructions and best practices. For example, you should check and adjust the alignment, the pressure, the temperature, the flow rate, or the voltage of your equipment, depending on the fabrication step, such as lithography, deposition, etching, or doping. You should also clean and inspect your equipment for any wear, damage, or contamination that can affect its functionality or accuracy.

4 Control your environment

The environment where you perform fabrication can also influence your yield and reliability. You should control your environment to minimize the exposure of your devices to dust, particles, moisture, or chemicals that can cause defects or degradation. For example, you should use clean rooms, filters, hoods, or gloves to reduce the contamination of your devices or your equipment. You should also monitor and regulate the temperature, the humidity, or the lighting of your environment, as they can affect the quality or the stability of your devices.

5 Train and supervise your operators

The human operators who handle your devices or your equipment can also affect your fabrication process. You should train and supervise your operators to ensure that they follow the standard operating procedures, the safety protocols, and the quality standards. For example, you should instruct and test your operators on how to use, clean, or store your equipment, how to load, unload, or inspect your devices, or how to record, report, or troubleshoot any issues. You should also motivate and reward your operators for their performance and feedback.

6 Analyze and improve your process

The last step to optimize your fabrication process is to analyze and improve your process based on the data and the results that you collect. You should measure and evaluate your yield and reliability using appropriate metrics, such as defect density, failure rate, mean time to failure, or lifetime. You should also identify and analyze the sources and the causes of any defects, failures, or variations that affect your yield or reliability. For example, you should use tools such as statistical process control, design of experiments, or failure mode and effects analysis to monitor, optimize, or prevent any problems in your process. You should also implement and verify any corrective or preventive actions that can improve your process.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?