JPH03171753A - Production system of semiconductor element - Google Patents

Abstract

PURPOSE:To keep fluctuation of an element characteristic at a minimum by providing a device for reading a semiconductor substrate number at each measuring equipment and a production device and by performing machining after determining machining conditions in a production device by a computer which recorded characteristic data of a semiconductor substrate unit. CONSTITUTION:After a polycrystal silicon is deposited onto a semiconductor substrate by a production device 3a, the film thickness is measured by a measuring equipment 3b, the number of a semiconductor substrate to be treated is read by a reading device 4, and they are transferred to and stored into a host computer 1. Then, after implanting ions by an ion implanting device 3c, rhos is measured by a measuring equipment 3d. Then, a doped polycrystal silicon layer is subjected to patterning by a lithography device 3e and resistance is measured by changing exposure conditions for each semiconductor substrate to be treated. Namely, after reading the semiconductor substrate number by the reading device 4, this number is transferred to the host computer 1. This host computer 1 calculates the amount of exposure from a desired pattern width W value for each semiconductor substrate number.

Description

[Detailed description of the invention] [Object of the invention] (Industrial application field) The present invention relates to a production system for semiconductor devices, and in particular,
Stable characteristics and quality can be obtained. (Prior Art) In manufacturing semiconductor devices, for example, a method is used in which passive devices and active devices are placed on a silicon semiconductor wafer (hereinafter referred to as a substrate) and then the wafer is divided into individual devices. By the way, while the process of assembling semiconductor elements has been automated for quite some time, the automation of the process of adding passive and active elements to semiconductor substrates started at a much newer time than the former. There is. The premise is that the basic data required to develop various elements has been accumulated, and this has greatly contributed to labor savings. As a result, production lines, which are set up with extremely precisely controlled and maintained cleanliness levels, have far less human interaction, which is the biggest source of waste, and It also greatly contributes to improving the yield of semiconductor devices with increased integration. on the other hand. As the dimensions of the single crystals required for semiconductor devices have improved, the size of the single crystals that are put into production lines is now larger than 5 inches or 6 inches, which has greatly improved productivity. The current situation is helpful. By the way, the labor-saving manufacturing line employs a computer control system, and the semiconductor substrates to be processed are processed in units of lofts (25 to 50 semiconductor substrates in one lot), and the processing unit is also in units of lots. Furthermore, in this computer control method, a measuring instrument connected to a computer is installed, and semiconductor elements having predetermined characteristic values are manufactured according to processing conditions determined by the computer from the results. Therefore, the characteristic values are measured by measuring one to several semiconductor substrates on which semiconductor elements are mounted, that is, one to several semiconductor substrates in a lot, and using the results as representative values. Additionally, processing data for manufacturing equipment is also set on a lot-by-lot basis.

(Problem to be solved by the invention) In this way, conventional manufacturing systems employ batch processing, and the characteristic data representing the loft is determined at only a few points, so it does not represent the characteristics of each individual semiconductor substrate. Moreover, the actual manufacturing process for semiconductor devices requires multiple processing steps, and in the end, variations that occur in a single process are amplified, resulting in large differences in individual characteristics. Become. The present invention was developed under these circumstances, and in particular, it is a method for individually managing the characteristic values of a semiconductor substrate on which semiconductor elements are mounted and feeding them back to the next process.
The purpose of this is to minimize fluctuations in the final device characteristics.

[Structure of the invention]

(Means for solving the problem) In a semiconductor device production system equipped with a computer that is online connected to a measuring device that measures the characteristics of a semiconductor device and a manufacturing device that drives the semiconductor device onto a semiconductor substrate, each measuring device A feature of the semiconductor device production system according to the present invention is that the manufacturing equipment is equipped with a device that reads the semiconductor substrate branch number, and the processing conditions in the manufacturing equipment are determined by a computer that records the characteristic data of each semiconductor substrate before processing. There is. (Function) In the system according to the present invention, a semiconductor substrate Nα (hereinafter referred to as a number) is attached to a characteristic measuring device operated after each processing step.
A reading device is attached, and the characteristics of the measurement results and the semiconductor substrate number are registered in the host computer. Even after this, the number of the semiconductor substrate to be processed is read and an algorithm (
The processing conditions for the semiconductor substrate are set using the algorithm. When processing semiconductor substrates in batches, the locations are determined and corrected based on the classification based on characteristic values and the tendency of the characteristic values based on the position known in advance. , for each semiconductor substrate. These series of correction processes are performed by computer processing. (Embodiments) Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 3. In other words, a series of processing steps that utilize manufacturing equipment and computers are based on the premise of appropriate inventory. FIG. 1 shows an outline of the present invention, and a measuring instrument/manufacturing device 3 is connected to a host computer 1 via an intermediate computer 2. The measuring instrument/manufacturing equipment 3 is attached with a semiconductor board number reading device w4. The arrows in the figure represent the flow of semiconductor substrates to be processed, that is, the order of processing.The host computer 1 and the intermediate computer 2 are connected via LAN, and the intermediate computer 2 and the measuring instrument/manufacturing equipment fi3 communicate on a one-to-one basis. Mainly SECS (Semiconductor)
erEquipmentCommunication
Standard) I, connected by ■, (
SECS-I corresponds to this) Also, the semiconductor board number reading device 1114 is 8I! Although it is connected to the measuring instrument/manufacturing equipment I13 or the intermediate computer 2, in FIG. ! 3 is shown connected. As an example of the processing procedure, we will explain it using a polycrystalline silicon resistor type process. First of all. After depositing polycrystalline silicon onto a semiconductor substrate using the manufacturing equipment 113a, the measuring device 3
The film thickness is measured by b, the number of the semiconductor substrate to be processed is read by the reader 4, and the measurement result is sent to the intermediate computer 2.
Transfer and save it to the host computer via . An example of the format is shown in FIG. 2, where the semiconductor substrate is referred to as a wafer. As is clear from this example, the product name, lot Nα, process name, lot representative value, wafer &1, and characteristic values are displayed, and of course the characteristic values are measured and displayed for each semiconductor substrate number to be processed. However, depending on the tendency of the characteristic values after processing in the manufacturing equipment 113, that is, the tendency of variation, it is not always necessary to measure all the semiconductor substrates.

Next, after ion implantation of an impurity of a predetermined conductivity type, for example, As, into a predetermined location of the polycrystalline silicon layer using an ion implantation device [3c],
Measure ρS using measuring device 3d. This step is also carried out using the same procedure as the processing using the measuring device 3b, but if there is little variation, measure several wafers, for example three, from the lot rather than all the semiconductor wafers, and use the average value as the loft representative value and enter it into the host computer l. save.

Next, lithography equipment
3e, the doped polycrystalline silicon layer is patterned, and the resistance value is controlled by changing the exposure conditions for each semiconductor substrate to be processed. The procedure is to read the semiconductor board number with the reading device w4 and then transfer this number to the host computer 1. In this host computer 1, the formula R =
Use ps-L/T-v. Here, R: target resistance value, ρs: measured value at 3d, L: design value, T: 3b
A value corresponding to the semiconductor substrate magnetic field measured in W: pattern width. A target value W is determined from this formula, and the exposure amount for obtaining W is determined by the method shown in FIG. In FIG. 3, the vertical axis represents the pattern dimension, the horizontal axis represents the exposure amount, and a straight line A indicating the relationship between the two is shown. This straight line A is determined by considering coefficients determined from empirical rules and theoretical values, and the exposure amount is determined by the straight line A from the desired pattern width W value.

In addition, as semiconductor devices equipped with one or both of active elements and passive elements, as well as resistors, etc., are becoming increasingly integrated, requirements regarding microfabrication and dimensional control are becoming stricter. is used, and the present invention also uses a positive resist. FIG. 4 shows a comparison of the resistance value b formed in this manner with that of the conventional example a. This figure shows the resistance value measurement result of polycrystalline silicon formed on n silicon semiconductor substrates as a bar graph, and it is clear that the resistance value b according to the present invention is less biased than the conventional example a. The resistance value obtained is also large. In figure a, the fifth bar from the left on the paper is the center value of the targeted resistance value, and in b, the third bar from the left on the paper is the center value of the targeted resistance value. This drawing can also be considered to prove the effectiveness of the present invention. [Effect of the invention] In the conventional technology, since the characteristic value is corrected and processed as a representative value of the loft, the variation between lofts does not become so large, and the center value approaches the target value, Variations within the loft, that is, variations between semiconductor substrates to be processed, are not corrected. For this reason, related processing variations result in amplification of final processing variations, whereas in the system of the present invention, variations due to processing steps are not increased and are corrected for each semiconductor substrate to be processed. As a result, for example, the variation in resistance value has been reduced to 172 or less than the conventional value. Obtaining accurate resistance values in this way satisfies the severe requirements recently placed on semiconductor integrated circuits, and greatly contributes to improving their characteristics.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an outline of the system of the present invention, FIG. 2 is an example of the data file format of a host computer used in the present invention, FIG. 3 is a diagram showing a method for determining processing conditions, and FIG. , is a diagram showing the effects of the present invention in comparison with a conventional example. 1: Host computer, 2a to 2e; Intermediate computer, 38 to 3e: Measuring instrument and manufacturing device, 48 to 4e: Semiconductor substrate reading device.

Claims (1)

[Claims] In a semiconductor device production system equipped with a computer that is online connected to a measuring device that measures the characteristics of a semiconductor device and a manufacturing device that drives the semiconductor device onto a semiconductor substrate, each measuring device and manufacturing device is assigned a semiconductor substrate branch number. 1. A production system for semiconductor devices, which is equipped with a reading device and is characterized in that the processing conditions for the manufacturing device are determined using a computer that records characteristic data of each semiconductor substrate before processing.