JPS587059B2 - Hakumaku No Tokusei Kensahou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION In recent years, thin film technology has been widely used for various electronic circuits or circuit elements.

For example, in a semiconductor device, a resistor thin film, a metal thin film, an insulating thin film, etc. are formed on a semiconductor substrate, and in a thin film element, a resistor thin film, a metal thin film, an insulating thin film, etc. are formed on an insulating substrate.

The present invention provides a thin film characteristic testing method suitable for use in testing the characteristics of such various thin films.

The present invention will be described with reference to FIG. 1. In the present invention, a semiconductor substrate 1 is prepared, and a thin film, for example, a metal thin film, whose characteristics are to be tested, is formed on one principal surface 1a of the semiconductor substrate 1. A thin film 2 such as a resistor thin film or a glass thin film is deposited.

A non-ohmic barrier, such as a PN junction J or a Schottky barrier, is formed in the semiconductor substrate 1 at least over the entire region where the thin film 2 is formed, along the thin film 2, that is, along the surface 1a.

For example, when the substrate 1 is made of an N-type semiconductor substrate, a P-type region 3 is formed facing one principal surface 1a by, for example, diffusion, epitaxial growth, etc. to form a PN junction J.

In this case, a thin film 2 is formed on the P-type region 3. and,
A charged particle beam, e.g., an electron beam 4, is accelerated to impact the thin film 2 of the base 1 from above the thin film 2 with the required energy in the same way as in a scanning electron microscope. is deflected by the horizontal/vertical deflection means 5 to sequentially scan at least the entire region of the thin film 2 whose characteristics are to be tested.

Reference numeral 6 denotes an emission source of the electron beam 4, that is, an electron gun.

Further, electrodes 7 and 8 are ohmicly applied to the P-type region 3 and the N-type region of the substrate 1, respectively, and the electrodes 7 and 8 are connected to the input end of the amplifier 9. is supplied to the cathode ray tube 10, thereby performing brightness modulation of the beam 12 of the cathode ray tube 10.

Reference numeral 11 denotes horizontal and vertical deflection means for the beam 12 of the cathode ray tube 10, and this deflection means 11 deflects the charged particle beam 4 onto the thin film 2.
The beam 4 is operated in synchronization with the deflection means 5, and the fluorescent surface 13 of the cathode ray tube 10 is scanned in synchronization with the scanning of the beam 4 on the thin film 2.

Thus, if the irradiation energy of beam 4 is appropriately selected,
The charged particles, in this example electrons, passing through the thin film 2 and reaching the substrate 1 generate pairs of holes and electrons.

Then, within the diffusion distance of holes and electrons, there is a barrier such as P
If an N junction J exists, holes and electrons are separated by this, an electromotive force is generated on both sides of the PN junction J, and both electrodes 7
An electromotive force signal corresponding to the amount of holes and electrons generated between 8 and 8 is extracted.

Then, this signal is amplified by an amplifier 9 and given to the cathode ray tube 10, and the beam 12 is intensity-modulated according to this signal, so that an optical image is obtained on the fluorescent surface 13 of the cathode ray tube 10. It will be done.

In this case, if there is a grain boundary in the thin film 2, the particles of the beam 4, such as electrons, will pass through the thin film 2 at this part.
Since the electrons are scattered between the particles, that is, at the grain boundaries, and are difficult to pass through the thin film 2, the number of hole-electron pairs generated in the substrate 1 under this portion is reduced, and the electromotive force is reduced.

Therefore, a signal is obtained between the electrodes 7 and 8 depending on the state of each part of the thin film 2, which is amplified by the amplifier 9 and applied to the cathode ray tube 10. An optical image corresponding to the size etc. is projected on the fluorescent surface 13.

Note that the state of electromotive force generation differs not only due to the existence of grain boundaries in the thin film 2, that is, the state of the particles, but also due to pinholes, cavities, uneven thickness, the state of contact with the substrate 1, etc. of the thin film 2. can be detected, and as a result, the characteristics of the thin film 2 can be known.

Therefore, for example, when it is unclear how a thin film formed during the manufacture of a semiconductor device or the like will be affected by a subsequent manufacturing process, such as a heat treatment process, a similar thin film may be formed on the substrate 1 in advance. Then, the substrate 1 is placed in this state and its characteristics are determined by the method of the present invention explained in FIG. By examining the characteristics of this thin film using the method of the present invention illustrated in FIG. 1, it is possible to examine how this thin film is affected by this heat treatment.

In the above example, P is used as a non-ohmic barrier in the substrate 1.
Although this is a case where an N junction J is formed, it can also be constructed from a Schottky barrier.

For example, if the thin film 2 to be inspected is a metal that can form a Schottky barrier with respect to the substrate 1, the Schottky barrier formed by the deposition may be used as a non-ohmic barrier.

[Brief explanation of the drawing]

The figure is a configuration diagram of an example of an apparatus for carrying out the thin film characteristic testing method according to the present invention. 1 is a semiconductor substrate, 2 is a thin film to be inspected, J is a PN junction, 7 and 8 are its electrodes, 9 is an amplifier, 10 is a cathode ray tube, 11 is its deflection means, 4 is a charged particle beam, and 6 is its emission source,
5 is its deflection means.

Claims (1)

[Claims] 1. A thin film to be inspected is deposited on a semiconductor substrate, a non-ohmic barrier is formed along the thin film to be inspected, and a charged particle beam is scanned from above the thin film to determine the non-ohmic barrier according to the scanning position. A thin film characteristic testing method for testing the characteristics of the thin film to be tested using an electromotive force signal generated in a barrier.