Various Kinds of Inspection are required in semiconductor industry production line: on-line inspection, critical dimension-measurement, and in-line inspection. Semiconductor Inspection System is the equipment used in manufacturing process of semiconductor device to detect the failure. Complete development of semiconductor device involves large manufacturing process. A failure at one step of the process, means to interrupt the subsequent step to avoid production of defective product. Hence insertion of inspection systems at the pivotal points of the process will ensure process moves to next step after confirming no defect at current step. Otherwise the production is interrupted if failure in the device is detected and the cause is determined followed by defect removal. Once the defect is sufficiently removed, the process is advanced to the next step in the process. Main defects in the semiconductor manufacturing process are pattern defects and small particles on semiconductor wafer.
Semiconductor Inspection System detects both the pattern defects and physical defects (foreign substances like particles) by obtaining the coordinates(X, Y) of the defect’s position. Determining position (Coordinates) on the wafer is the primary role of the Semiconductor Inspection System. Inspection can be done on both patterned and bare wafer. Inspection systems for patterned and non-patterned wafer have different configurations. Based on configuration patterned inspection systems are categorized as bright field, electron beam, and dark field inspection systems. Non-patterned inspection system is used in equipment check by dummy wafers for cleanliness monitoring of the equipment. Physical Defects that are caused by foreign particle are called random defects as their position (i.e. coordinates) cannot be determined. On the other hand systematic defects are the defects which are result of exposure and conditions of the mask. They occur at the same position and hence are detectable by the inspection systems. These inspection systems are hence indispensable to maintain production yield of semiconductors.
Rise in demand for high performing and low cost semiconductors will augment the use of inspection systems. Growing complexity of the process and design of semiconductor chip is also significant factor in growth of the market for semiconductor inspection systems. Increasing demand for notebooks, gaming consoles, smartphones, tablets, network switches, digital cameras, and set-top boxes will propel the requirement of foundries. Increasing proliferation of loT (Internet of Things) is also the growth driver. Rising need of semiconductor memory devices like 3D NAND and DRAM is also attributed to growth of the market. The main challenge posed to the industry is introduction of multi-layer wiring and planarization process in manufacturing of semiconductor devices which existing inspection systems are incapable to detect.