Process yield

Definition

Process yield refers to the percentage of usable product obtained from a manufacturing process compared to the total amount of material that was input into that process. A high process yield indicates efficient production with minimal waste, while a low yield signifies issues such as defects or inefficiencies that can impact overall productivity and cost-effectiveness in manufacturing.

5 Must Know Facts For Your Next Test

1. Process yield is crucial in determining the cost-effectiveness of lithography and etching processes, as higher yields lead to lower production costs per unit.
2. Variations in parameters such as exposure time, development conditions, and etch depth can significantly affect process yield during lithography and etching.
3. In semiconductor manufacturing, achieving high process yields is essential for profitability, as even small reductions can lead to substantial financial losses.
4. Improving process yield often involves iterative testing and refinement of the fabrication processes to identify and eliminate sources of defects.
5. Tools such as statistical process control (SPC) are frequently employed to monitor and improve process yields throughout the production cycle.

Review Questions

• How does process yield influence the overall efficiency of lithography and etching processes in semiconductor manufacturing?
  • Process yield directly affects the efficiency of lithography and etching by determining how many usable chips can be produced from a batch of wafers. A higher yield means more functional devices are created from each wafer, reducing costs associated with material waste and reprocessing. Therefore, optimizing process parameters to enhance yield is essential for maintaining competitiveness in semiconductor manufacturing.
• Discuss the relationship between defect density and process yield in the context of lithography and etching techniques.
  • Defect density is inversely related to process yield; as defect density increases, process yield typically decreases. High defect levels can result from issues during lithography exposure or etching, leading to unusable products. Manufacturers strive to reduce defect density through careful calibration of equipment and materials, thereby improving overall yield and ensuring higher quality products.
• Evaluate the impact of improving process yield on production costs and profitability in semiconductor fabrication.
  • Improving process yield can significantly lower production costs by maximizing the number of functional devices produced from each fabrication run. As yields increase, the cost per usable chip decreases, directly boosting profitability. This improvement also enhances competitiveness in the market by allowing manufacturers to offer more cost-effective products while maintaining quality standards, thus ensuring long-term sustainability in an industry characterized by high research and development expenses.

Related terms

Defect Density: The number of defects per unit area in a manufacturing process, often used to assess the quality of the produced items.

Throughput: The rate at which a system produces its output over a given period, indicating the efficiency of the manufacturing process.

Wafer Fabrication: The process of creating integrated circuits on semiconductor wafers, where process yield plays a crucial role in determining the number of functional chips produced.