JPS63220536A - Evaluation of radiation resistance of integrated circuit - Google Patents

Abstract

PURPOSE:To predict the radiation resistance of an IC, in which there is no experimental data, by predicting the radiation resistance of an integrated circuit, a manufacturing process and the degrees of integration of which are known, by using the relationship of the degrees of integration at every manufacturing process and radiation resistance. CONSTITUTION:The device consists of a CRT 1 displaying the result of the prediction of the radiation resistance of an IC, a keyboard 2 for inputting data, a memory 5 previously storing a control program for the device, a CPU 4 controlling the device according to the program, a disk 6 for storing the radiation-resistant data of the IC and a bus 3 connecting these parts. The ICs are sorted by manufacturing processes, and the relationship of the radiation resistance of the ICs and the degrees of integration of the ICs in a sorted IC group is acquired previously from the radiation-resistant data of a small number of the ICs. The radiation resistance of the ICs having unknown radiation-resistant data is predicted by using beforehand obtained said relationship, employing the manufacturing processes and degrees of integration of the ICs as data. Accordingly, radiation resistance can be predicted when manufacturing processes and the degrees of integration are determined regarding even the ICs in which there is no expenrimental data of radiation resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for evaluating the radiation resistance of an integrated circuit, and particularly to a method for evaluating the radiation resistance of an integrated circuit suitable for designing electronic circuits.

[Conventional technology]

The radiation resistance of integrated circuits differs from one integrated circuit to another, as reported in pages 27 to 34 of the 1985 National Space Exploration Agency Commissioned Work Results Report.

For this reason, radiation resistance has conventionally been evaluated by conducting experiments for each type of integrated circuit.

[Problem that the invention seeks to solve]

Electronic circuits are designed using many types of integrated circuits (hereinafter referred to as ICs). On the other hand, in order to evaluate the radiation resistance of a designed electronic circuit, it is necessary to know the radiation resistance of each IC used. However, since there are so many types of ICs on the market, it is extremely difficult to evaluate the radiation resistance of all ICs in advance using the conventional evaluation method described above (the radiation resistance of electronic circuits is There are very few cases in which all the radiation resistance data of the IC used for evaluation is known.)

An object of the present invention is to make it possible to predict the radiation resistance of an IC for which there is no experimental data from the limited experimental data for evaluating the radiation resistance of an IC.

[Means for solving problems]

The above purpose is to classify ICs according to their manufacturing process, and to obtain in advance the relational expression between the radiation resistance of ICs and the degree of integration of ICs among the classified IC groups from the radiation resistance data of a small number of ICs. This is achieved by predicting the radiation resistance of an IC for which radiation resistance data is unknown, using the manufacturing process and degree of integration of the IC as data, and using the corresponding relational expression determined previously.

[Effect]

It has been found that the radiation resistance of an IC varies with the degree of integration given the same manufacturing process.

Therefore, by evaluating the radiation resistance of typical ICs through experiments and formulating the relationship between radiation resistance and degree of integration in advance, it is possible to evaluate the manufacturing process and degree of integration even for ICs for which there is no experimental data on radiation resistance. If we know this, we can predict the radiation resistance.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. FIG. 1 is a block diagram of an embodiment of the present invention. This device measures the radiation resistance of an IC (generally expressed as the radiation dose at which abnormalities begin to occur, hereinafter referred to as radiation resistance).

), a keyboard 2 for inputting data, a memory 5 for storing the control program of this device, a C P tJ 4 for controlling the device according to the program, and radiation resistance of the IC. It consists of a disk 6 for storing data and a bus 3 connecting them.

The operation of this device will be explained below with reference to FIG.

FIG. 2 is a flowchart of the control program.

The program is broadly divided into two parts. One is the data registration part L1 to L6, the other part is the radiation resistance prediction part,
10 to L14.

First, the data registration part will be explained. The operator inputs the IC manufacturing process name using the keyboard 2.

ICs that use silicon or G
There are some that use a A s. Taking silicon-based devices, which are currently mainstream, as an example, they can be divided into bipolar type and MOS type, depending on the type of basic transistors that make up the IC. The above-mentioned manufacturing process starts with the basic materials used and types of basic transistors, and includes detailed specifications such as the method for manufacturing the pn junction of the transistor, the structure and size of the element, and the method for manufacturing the IC. To tell. Each manufacturer typically has multiple manufacturing processes, each with a unique name.

Even if ICs 1 having the same function, such as TTL's 7400 series, are made by different manufacturers, the manufacturing process will differ in the details, so the radiation resistance will differ.

The input manufacturing process name data is taken in by the CPU 4 at L2 and registered on the disk 6. Next, the operator registers data on the degree of integration and radiation resistance of the IC (from the registered manufacturing process) whose radiation resistance has already been confirmed through experiments (L3-L4).

When the data input is completed, the CPU calculates a relational expression between the degree of integration and the radiation resistance (L5). In this embodiment, fitting is performed using the least squares method. The calculated formula is registered on the disk 6 in association with the manufacturing process name (T, 6).

The above registration is repeated for a plurality of manufacturing processes.

Next, prediction of radiation resistance will be explained. The operator uses the keyboard 2 to input the name of the IC manufacturing process to be predicted. CPU 4 takes in the data (LIO)
. Furthermore, the operator inputs the degree of integration of the IC (the number of integrated transistors), and the CPU 4 takes it in (Lll).
Next, the CPU 4 searches for a relational expression from the disk 6 using the imported manufacturing process name (L12). From the IC integration degree and its relational expression, the radiation resistance of the IC can be calculated, and the CR
The calculation result is displayed on Tl (T, 14).

FIG. 3 shows an example of a display on a CRTl. The manufacturing process name of the IC whose radiation resistance dose should be predicted is in the manufacturing process name display column 1o.
Then, the degree of accumulation is displayed in the degree of accumulation display column 11. Relational expression 1
The radiation resistance calculated in step 3 is displayed in the radiation resistance display column 12.
is shown. Generally, as shown in this figure, as the degree of integration increases, the radiation resistance decreases.

According to this embodiment, there is an effect that the radiation resistance of an IC for which there is no experimental data can be easily predicted.

〔Effect of the invention〕

According to the present invention, the radiation resistance of an integrated circuit for which there is no radiation resistance experimental data can be easily predicted from radiation resistance data of known integrated circuits.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a flowchart of a control program, and FIG. 3 is a CRT display screen diagram. 1... CRT, 2... Keyboard, 3... Bus,
4...CPU, 5...Memory, 6...Disk,
10... Manufacturing process name display column, 11... Integration degree display column, 12... Radiation resistance display column, 13... Relational expression display. Patent applicant: Director of the Agency of Industrial Science and Technology Juzo Iizuka No. 1 Figure No. 2 Country

Claims (1)

[Claims] 1. In the method of evaluating the radiation resistance of integrated circuits, the relationship between the degree of integration and radiation resistance is determined from the actually measured radiation resistance data of integrated circuits for each integrated circuit manufacturing process, and the relationship between the degree of integration and radiation resistance is calculated for each manufacturing process. A method for evaluating the radiation resistance of an integrated circuit, the method comprising predicting the radiation resistance of an integrated circuit whose manufacturing process and degree of integration are known, using the relationship between radiation resistance and radiation resistance.