JPH0281399A - Non-destructive processing method for integrated circuit - Google Patents

Abstract

PURPOSE:To not necessarily make it unnecessary to use material to transmit ultraviolet ray to the material used for the protective film and package of an EPROM while it can shift to a stable condition different before irradiation by irradiating an electromagnetic wave set to the wavelength of the characteristic X ray of an object to constitute an integrated circuit and exciting an electron in the integrated circuit. CONSTITUTION:An electromagnetic wave set to the wavelength of the characteristic X ray of an object to constitute an integrated circuit is irradiated and an electron in the integrated circuit is excited. Namely, by the irradiation of the electromagnetic wave, the electron in the integrated circuit is excited, jumps over the potential wall due to an insulating film and the like, spreads to the circumference and shifts to the stable condition different from the stable condition before irradiation. Consequently, the memory contents can be erased even for the EPROM to use a protective film and the package not to transmit the ultraviolet ray. Thus, it is eliminate that the material of the protective film and package of a chip must be the one to transmit an ultraviolet ray 14.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is a non-destructive process for integrated circuits that can be applied, for example, to erasing ultraviolet-erasable EFROM memories whose surfaces are covered with a protective film or package that does not transmit ultraviolet rays. It is about the method.

(Prior Art) FIG. 2 is a sectional view showing an ultraviolet erasable EPROM. In this figure, 11 is an EFROM chip, 12 is a protective film covering the surface of the chip 11, 13 is a package, 14 is an ultraviolet ray, and 15 is a glass serving as a window through which the ultraviolet ray 14 is transmitted.

Normally, in such an EPROM, when erasing information written in the memory cell, ultraviolet rays 14 are irradiated, and the irradiated ultraviolet rays 14 pass through the glass 15 and the protective film 12. The memory cells in the chip 11 are irradiated, giving the electrons accumulated in the memory cells enough energy to pass through the surrounding insulating layer. That is, information written in the memory cell is erased by the electrons excited by the ultraviolet rays 14 passing through the insulating layer and diffusing.

However, since it is manufactured under the constraint that the memory contents must be erased by irradiation with ultraviolet rays 14, the materials of the protective film 12 of the chip 11 and the package 13 must be transparent to the ultraviolet rays 14. I had to.

[Problem to be solved by the invention]

In the erasing method using ultraviolet rays as described above, one-time F
Since it was impossible to erase the information in the windowless plastic mold packaged EFROM that is commercialized as a ROM, there were major limitations in screening for defective one-time FROM products and in how they were used.

This invention was made to solve the above-mentioned problems, and provides a non-destructive processing method for integrated circuits that can erase memory contents even in EFROMs that use protective films and packages that do not transmit ultraviolet rays. The purpose is to

(Means for Solving the Problems) A method for non-destructive processing of integrated circuits according to the present invention excites electrons in the integrated circuit by irradiating electromagnetic waves set to the wavelength of characteristic X-rays of the material constituting the integrated circuit. It is something.

(Function) In this invention, the electrons in the integrated circuit are excited by the irradiation of electromagnetic waves, and they jump over the potential wall formed by the insulating film and diffuse to the surroundings, thereby creating a stable state before irradiation and another stable state. to move to.

〔Example〕

FIG. 1 is a sectional view showing an EPROM in a windowless plastic mold package to which the present invention is applied. In this figure, 1 is an EFROM chip, 2 is a protective film covering the surface of the chip 1, 3 is a windowless plastic mold package, and 4 is an X-ray.

Next, a memory erasing method according to the present invention will be explained.

First, when X-rays 4 are irradiated, the irradiated X-rays 4 pass through the plastic mold package 3 and the protective film 2 and excite the electrons stored in the memory cells within the chip 1. In other words, the electrons will be given enough energy to pass through the insulating layer surrounding the memory cell, so the electrons will diffuse through the insulating layer, erasing the information written in the memory. Ru.

Usually, the elements that make up the part that accumulates electrons are mainly Si.
and P, and in order to give energy to the electrons orbiting these and cause them to diffuse, it is necessary to irradiate them with X-rays of the following wavelengths.

For P, α1 is 1.35 people, K for Si (El is 1.66 people, LllL+ for P is 11.8 people, LcLI for Si is 15.4 people) By the way, in order to reduce the damage to the integrated circuit, the wavelength must be Since it is necessary to use X-rays for a long time, it is optimal to use X-rays with a wavelength of about 10 people.

In the above embodiment, an EFROM whose package is a plastic mold package has been described, but the same applies to an EFROM whose package is made of a material such as ceramic that transmits X-rays.

Further, if the same effect can be expected even if radiation other than X-rays is irradiated, radiation other than X-rays may be irradiated.

Furthermore, the memory contents may be erased by irradiating the wafer-shaped memory with X-rays, and in this case, the protective film of the chip does not need to be transparent to ultraviolet rays.

Furthermore, this invention is not limited to only erasing memory contents; by irradiating radiation that passes through an opaque material, electrons unevenly distributed inside the material are given energy to overcome the potential wall. Needless to say, it can be used for all purposes to transition to a stable state different from that before irradiation.

〔Effect of the invention〕

As explained above, this invention excites the electrons in the integrated circuit by irradiating electromagnetic waves set to the wavelength of characteristic X-rays of the material constituting the integrated circuit. , it jumps over the potential wall caused by the insulating film, etc., and begins to diffuse to the surroundings, shifting to a stable state different from that before irradiation. Therefore, it is no longer necessary to use materials that transmit ultraviolet rays as the materials used for the protective film and package of the EFROM, which has the effect of making it possible to stably manufacture the EFROM. Further, if this method is used for screening one-time FROM, it becomes possible to write and erase a plurality of data, so that sufficient screening becomes possible.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an EFROM in a windowless black mold package to which the present invention is applied, and FIG. 2 is a sectional view showing a conventional ultraviolet erase type EFROM. In the figure, 1 is the EFROM chip, 2 is the protective film, and 3 is the EFROM chip.
is a plastic mold package, and 4 is an X-ray.

Claims (1)

[Claims] An integrated circuit characterized by irradiating electromagnetic waves set to the wavelength of characteristic X-rays of materials constituting the integrated circuit to excite electrons in the integrated circuit and causing them to transition to a stable state different from the stable state before irradiation. A non-destructive processing method for circuits.