JPH02137215A - Manufacture of semiconductor integrated circuit - Google Patents

Abstract

PURPOSE:To enable an operator to know a position of a subject substrate in process procedures and te avoid his erroneous operation by engraving characters or symbols indicating treating equipments and treating conditions of two or more processes of manufacturing an integrated circuit on semiconductor substrates to be treated and checking off the marks upon completion of each process. CONSTITUTION:Using an Si substrate of 6 inches for example, codes of up to 300 processes are written by SEMI standard characters along the periphery on the surface of the substrate. Along the orientation flat on the surface of the semiconductor substrate, there are recorded item names by 8 digits for example. Upon completion of each treating process, these codes are checked off. A laser marker is used for such check-off and for marking the former process procedure codes.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for manufacturing a semiconductor integrated circuit.

[Conventional technology]

In the conventional manufacturing of semiconductor integrated circuits, a method is used in which a plurality of semiconductor substrates are placed in a tray and each manufacturing process is performed using the tray as a management unit. A plurality of semiconductor substrates placed in the same tray are processed simultaneously to form one lot. At this time, the control tag attached to the tray is usually used as a basis for identifying the process position of the lot. The tray number may also be used for that purpose. Furthermore, in highly automated factories,
In some cases, a code for identifying the board is marked on the semiconductor board, and this code is used as the basis for management.

When a control tag is used, the process steps and processing conditions for the lot to be processed are written directly on the control tag. When a worker picks up a lot to be processed (a tray containing semiconductor substrates and a control tag), the operator learns the processing conditions by looking at the control tag, processes the substrates, and ends the process when the process is completed. Record what you have done on the management tag. The lot is then sent to the next process by knowing the processing equipment for the next process from the control tag.

On the other hand, when using tray numbers or codes marked on semiconductor substrates, the process steps to be processed, processing conditions, and current process positions are recorded on the host computer that controls all manufacturing lines, and the By interacting with it, the user learns the processing conditions and proceeds with the process.

[Problem to be solved by the invention]

In the conventional semiconductor integrated circuit manufacturing method described above, when using control holes and tray numbers, correspondence with the semiconductor substrate is not necessarily guaranteed, and there is a possibility of operator error or failure of manufacturing equipment. Correspondence often deviates due to malfunctions, etc. This is because the manufacturing process of semiconductor integrated circuits uses the same equipment many times in different processes, and because the manufacturing equipment processes a large number of semiconductor substrates at the same time, multiple lots enter the equipment and process at the same time. The main cause is the need to transfer the waste from transport trays to special trays when processing in equipment. In addition, using the tray number and identification code written on the semiconductor substrate itself,
In the case of management using a host computer on the production line, computer machine failure cannot be predicted in advance, and discrepancies between the data on the computer and the actual data are unavoidable. This causes a problem that the current process of the lot becomes unclear. In addition, dedicated LSIs (so-called custom LSIs) are required to produce a wide variety of products in small quantities, and the diameter of semiconductor substrates continues to increase in size, and the number of semiconductor substrates required for production is decreasing. However, the number of lots continues to increase. In such a situation, conventional management using management holes and tray numbers becomes complicated, and from this point of view, it is easy to make mistakes.

[Means to solve the problem]

In the method for manufacturing a semiconductor integrated circuit of the present invention, characters or symbols indicating the processing equipment and processing conditions for at least two or more steps of manufacturing the integrated circuit are imprinted on the semiconductor substrate to be processed before the steps are performed. means for checking off the character or symbol at the end of the process.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIGS. 1(a) and 1(b) are a plan view and a partially enlarged plan view of a semiconductor substrate showing a first embodiment of the present invention. CMOS using Si, a typical semiconductor integrated circuit manufacturing process
The manufacturing process involves approximately 300 steps and uses approximately 4 pieces of equipment.
0 equipment, the processing conditions for each equipment are several to several dozen conditions for each equipment, and at most 99 conditions or less. For this reason, a two-digit code representing equipment and a two-digit code representing conditions are sufficient.

Therefore, the code to be adopted is 4 digits, the first 2 digits being the equipment code,
The last two digits are the condition code. As a result, as in the example shown in FIG.
It can be used to inject 015cra-2. In this embodiment, a 6-inch Si substrate is used. In this case, the surrounding equipment is 478, 77+nm.

The circumference inside 5mm is 447.36mm. It is assumed that all 300 processes are written on a semiconductor substrate. The letter to use is S
E M I (Sem1conductor Equ
ipment and Materials In5ti
tute) as the standard character. Figure 2 (a) is an enlarged version of this character, and the actual dimensions are shown in Figure 2 []
The width is 0 as shown using the outer frame of the SEMI character in (b).
, 406±0.025mm, height 0.812±0.
0.25 mm, and the pitch is 0.71±0.025 mm. Therefore, the 4-digit code is 2.536mm x 0.
It can be written at 812mm, and 5m as shown in Figure 1.
m If you write this code radially in the process order between the inner circumference and the outer circumference of the board so that it touches the inner circumference, the interval is 0.30.
Since it is 4 mm, the pitch on the inner circumference side is 812+0.
304-1.116 (mm), and in 300 processes, it is possible to write 1.116 x 300 = 334.8 mm, which is sufficient to write on the outer circumference of the surface of the substrate.

Further, in this embodiment, the product name is written in eight digits at a position 5 mm inside the substrate on the orientation flat of the semiconductor substrate. This is because if the equipment is an exposure machine, the mask to be used can be known from the product name and process order.

Each time one processing step is completed, the corresponding code is checked off. A laser marker is used to mark this check-off and first process order code. The correspondence between the processing condition code and the details of the actual processing condition may be stored in the controller of the relevant equipment.

In the first embodiment, all processes were written and checked off, but in the second embodiment, the present invention was applied only to processes such as ion implantation and heat treatment that do not remain as a pattern and cannot be reprocessed. apply.

In the manufacturing process of semiconductor integrated circuits, there are processes such as water washing and cleaning that can be processed again, as well as PR processes, etching processes, etc., where it is possible to determine whether the process has been completed by looking at the pattern formed on the substrate. There is a process that allows you to determine whether or not it is possible.

Such steps are managed in the same way as conventional methods, and the present method is applied to ion implantation and heat treatment steps. The code marked on the board and the marking method are the same as in the first embodiment. By doing so, there is no need to check off the corresponding codes on all process boards each time, and it is possible to eliminate accidents in which the process position of the relevant board becomes unknown.

〔Effect of the invention〕

As described above, according to the present invention, by writing a code corresponding to the processing equipment and processing conditions directly on the semiconductor substrate to be manufactured, two workers are made aware of the position of the substrate in the process procedure, It is possible to eliminate work errors and reduce the number of defective lots. In the embodiment, a laser marker was used to mark the semiconductor substrate, but other methods are also effective, such as marking characters by exposure or etching, and checking off by using a diamond point. Furthermore, although SEMI characters have been used as marking characters, other characters or codes may also be used.

[Brief explanation of the drawing]

1(a) and 1(b) are a plan view and a partially enlarged plan view of a semiconductor substrate for explaining the first embodiment of the present invention, and FIG.
Figures (a> and (b) are diagrams showing examples of codes according to the first embodiment. 1... Semiconductor substrate, 2... Code entry frame, 3...
Product name entry frame.

Claims (1)

[Claims] In a method for manufacturing semiconductor integrated circuits, characters or symbols indicating the processing equipment and processing conditions for at least two or more of the relevant integrated circuit manufacturing steps are imprinted on the semiconductor substrate to be processed before the execution of the relevant steps, and A method for manufacturing a semiconductor integrated circuit, characterized in that the character or symbol is checked off at the time of completion.