JPH0241173B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a semiconductor wafer processing method that requires two or more inspection items.

The manufacturing of semiconductor devices requires a large number of manufacturing processes, and if quality control during each manufacturing process is not sufficient, there is a risk of producing a large number of defective products.Therefore, quality control, that is, semiconductor inspection (including measurements) are considered extremely important. For this reason, conventional techniques have been used to (1) inspect the state of fine foreign matter adhering to semiconductor substrates (foreign matter inspection), (2) inspect the thickness of thin films formed on semiconductors (thin film measurements), and (3) inspect the pattern shape and shape formed on semiconductors. A wide variety of inspection items, including dimensional inspection (pattern inspection), are carried out in a wide variety of processes.

By the way, conventionally, these inspections are performed by single-function inspection, in which one inspection item is performed by one inspection machine. For this reason, when there are two or more inspection items, the problem arises that the work is troublesome and the work efficiency is low. For example, after the thin film forming process, which is one of the semiconductor manufacturing processes, there is a foreign object inspection and a thin film thickness measurement, but in the past, these inspections were performed completely independently and individually, so each inspection machine Then, each wafer to be tested must be set and reset one by one. In addition, in conventional inspections, each inspection machine is independent and there is little correlation with each other, so even if a defective product is found in the inspection results, it is difficult to systematically identify the cause of the defect and take appropriate measures. Problems have also arisen.

Therefore, an object of the present invention is to enable highly effective and automatic inspection of semiconductor wafers;
Moreover, it is an object of the present invention to provide a method for manufacturing semiconductor wafers that can prevent the manufacture of defective semiconductors as much as possible by analyzing the causes of defects.

Hereinafter, the present invention will be explained based on illustrated embodiments.

FIG. 1 is a flowchart of an embodiment of the present invention for forming a thin film on a semiconductor wafer, and a test for the number of fine foreign objects and a test for the thickness of the thin film are performed between the thin film forming process as a pre-process and the next process. That's what I do. Good products from each inspection are sent out in sequence according to the regular flow, but products that are defective in the minute foreign matter count test or products that are defective in the thickness test and whose film thickness is larger than the standard are treated as defective. Furthermore, even if the thickness test fails, those whose film thickness is smaller than the standard are recycled and subjected to the thin film forming process again.

FIGS. 2 and 3 show an embodiment of the present invention for carrying out the above steps, and 1 is a foreign matter inspection machine;
2 is a thinness inspection machine. The foreign matter inspection machine 1 is installed downstream of the thin film forming step 3, and a foreign matter detection optical system 6 is installed above a sample stage 5 on which a wafer 4 as an object to be inspected is placed. Detects foreign objects. A magazine 7 as a loader is installed at the upstream position of the sample stage 5, and the wafers (wafers with a thin film formed on the surface by a thin film forming process) 4 stored in the magazine 7 are transferred onto the sample stage 5 by a transport truck 8. Transfer one sheet at a time. Reference numeral 9 denotes an XY table, which moves the sample stage in XY.

On the other hand, the thinness inspection machine 2 includes the foreign matter inspection machine 1.
A film thickness measuring device 11 is disposed downstream of the sample stage 10 on which a wafer can be placed, and above the sample stage 10 on which a wafer can be placed. Further, transport trucks 12,
13, and a plurality of magazines 14, 15, which serve as an unloader capable of storing new wafers are provided at further downstream positions of the truck 13 on the downstream side.
16, the wafer 4 from the foreign object inspection machine 1 is moved onto the sample stand 10 by the magazine 12, and the wafer on this sample stand 10 is further moved into the magazines 14, 15, 16 by the truck 13. And store it. Magazines 14, 15, 16 are good items,
Each magazine is provided as a magazine for defective products and a recycled product, and the wafers are sorted into one of the magazines 14,
Store it in 15 and 16.

Furthermore, the foreign matter detection optical system 6 and the film thickness measuring device 11
are electrically connected to the magnetic storage device 17, respectively, and input the detection results of the optical system 6 and the measuring device 11 to the computer 18. The computer 18 totalizes the detected values based on each detected value, determines the quality of the wafer according to a predetermined program, and operates the sorting mechanism. Furthermore, the computer 18 has a function of estimating the cause of film thickness defects due to foreign matter based on the detection results, and can operate and control the control mechanism of the thin film forming step 3 according to the estimation results.

According to the above configuration, the wafer 4 that has completed the thin film forming step 3 is temporarily stored in the magazine 7, and then transported to the sample stage 5 of the foreign object inspection machine 1 by the transport truck 8.
The foreign object detection optical system 6 performs a foreign object inspection thereon. The output of the test is input to a magnetic storage device 17 and a computer 18. Next, the wafer is transferred to the thin film inspection machine 2 by the transport truck 12.
The film thickness measuring device 1 is moved onto the sample stage 10.
1, the film thickness is measured. At this time, the wafer determined to be defective by the foreign object inspection is not stopped on the sample stage 10, but is further moved by the transport truck 13 and stored in the defect magazine 15. Furthermore, the wafers whose film thickness has been measured are moved downstream on the transport truck 13, with non-defective products being transferred to the non-defective product magazine 14, defective products with a small film thickness being transferred to the recycling magazine 16, and defective products having a large film thickness being transferred to the recycling magazine 16. The computer 18 operates the sorting mechanism so that the defective products are stored in the defective product magazine 15. The results of each test are sent to the computer 18 via the magnetic storage device 17.
When inputted, the computer 18 analyzes the test results, estimates or determines the causes of foreign matter adhesion and film thickness, and performs feedback control of the thin film forming process 3 to prevent the occurrence of defective products.

Therefore, according to this embodiment, the wafers that have undergone the thin film forming process can be continuously inspected for foreign matter and film thickness, and these inspections can be performed automatically, which simplifies the work. It is possible to achieve improvements in work efficiency as well as to increase efficiency. Further, by analyzing the cause of defects, it is possible to prevent the occurrence of defective products in the thin film forming process as quickly as possible.

In addition, in the above example, the foreign matter inspection and film thickness measurement between the thin film forming process and the next process were explained, but this is not limited to this process and inspection, and can be similarly performed in other processes and inspections. can.

As described above, according to the semiconductor manufacturing wafer processing method of the present invention, two or more inspection machines are mechanically integrated, and each inspection machine is connected to a computer capable of analyzing the cause of defective products. Since the structure is configured to automatically control the operation of semiconductor pre-processes based on the cause of failure, various inspections between semiconductor manufacturing processes can be performed automatically and with high efficiency, and the cause of failure can be automatically controlled. This analysis has the advantage that manufacturing of defective semiconductors can be prevented as quickly as possible.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing the manufacturing and inspection steps of an embodiment of the present invention, and FIGS. 2 and 3 are a plan view and a front view of an apparatus according to an embodiment of the present invention. 1... Foreign object inspection machine, 2... Thin thickness inspection machine, 3...
Pre-process (thin film forming process), 4... wafer, 6...
...Foreign object detection optical system, 11...Film thickness measuring device, 14,
15, 16...magazine, 18...computer.

Claims (1)

[Claims] 1. In a semiconductor wafer processing method for processing a semiconductor wafer through a plurality of processing steps, a foreign matter inspection means is provided between a thin film forming step of the plurality of processing steps and the next processing step after this thin film forming step; An inspection process having a continuous film thickness measurement inspection unit is provided after the foreign substance inspection unit, and each inspection result of the inspection process is inputted to a computer that analyzes the cause of failure of the defective product to determine the cause of failure of the defective product, Based on this determination result, the processing conditions of the thin film forming step are controlled, and the semiconductor wafers determined to be non-defective in the foreign matter inspection are sent to the film thickness measurement inspection, and furthermore, the semiconductor wafers determined to be good in the foreign matter inspection are sent to the film thickness measurement inspection, and the film thickness is determined to be small in the film thickness measurement inspection. A method for processing a semiconductor wafer, characterized in that the semiconductor wafer that has been determined is returned to the thin film forming step for regeneration.