JPS6058623A - Pattern formation - Google Patents

Abstract

PURPOSE:To make unnecessary the successive heat processings by selective irradiation of energy particles or X-ray under the condition that a substrate to be processed is kept under the heated condition. CONSTITUTION:A Si oxide film 2 and phosphorus-added polycrystalline Si film 3 are stacked on a Si substrate 1 and it is used as a substrate 4 to be processed. A negative electron beam resist film 5 is formed by bonding on the substrate 4. This substrate 4 is heated by a heating source 6 and the film 5 is selectively irradiated with electron beam 7 under this condition. The film 5 is developed and the lower layer films 3, 2 are removed by etching with the resist film 5' after development used as a mask. According to this method, generation of damage by irradiation of high energy electron beam can be suppressed and therefore successive heat precessings can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to a pattern forming method using high-energy particle beams and electromagnetic waves.

[Prior Art and its Problems] As the degree of integration of semiconductor devices, including VLSIs, increases, there is a need for pattern forming technology that uses fine pressure and has high precision. As techniques for forming fine turns of 1 μm or less, direct writing methods using electron beams or ion beams, X-ray exposure methods, etc. are being adopted in place of conventional photolithography techniques. However, these pattern forming methods, for example,
(Metal-Oxide-Sem1condu
When applied to the manufacturing of MO8 devices, positive fixed charges, neutral capture centers, interface states, etc. are generated in the silicon oxide film (8i0z) or at the silicon (Si)-silicon oxide film interface, and the characteristics of the MO8 device are It is well known that it causes deterioration.

In order to obtain a high-performance, highly reliable MO8 element, it is necessary to eliminate or reduce these damages.

For this purpose, a method is usually adopted in which the element substrate is heat-treated after pattern formation. This heat treatment process is a separate process from the pattern formation process, and is unnecessary in the MOS device manufacturing process using conventional photolithography technology, but is newly added in the manufacturing process using high-energy beams and X-rays. It is a process.

Therefore, the productivity of devices using high-energy beam X-rays is significantly lower than when using conventional photolithography techniques.

[Object of the Invention] The present invention has been made in view of the above-mentioned problems, and provides a pattern forming method using predetermined energy quantum beams or X-rays that does not require a subsequent heat treatment step.

[Summary of the Invention] The gist of the present invention is to selectively irradiate a particle beam or X-ray of a predetermined energy onto a particle beam- or In this method, the selective irradiation is performed while the temperature of the substrate to be processed is maintained at a predetermined temperature.

[Effects of the Invention] According to the present invention, semiconductor elements such as silicon with excellent characteristics can be processed using high-energy particle beams and X-rays without increasing the number of steps.
It can be manufactured using phosphorography technology using lines.

[Embodiments of the Invention] A case in which a polycrystalline Si gate MOS capacitor is manufactured as an embodiment of the present invention will be described with reference to the drawings. 1st
The figure shows, for example, an 8i oxide film 2 with a thickness of ~300X on a Si substrate 1 with a specific resistance of 0.05Ω・α, and an oxide film 2 with a thickness of ~50X, for example.
oX phosphorus-doped polycrystalline Si film 3 is laminated in this order,
This is a process sectional view showing a state in which a negative electron beam resist film 5 having a thickness of 3,000 mm or more is deposited on the substrate 4 to be processed as a particle beam sensitive film.

Next, as shown in FIG. 2, the resist film-coated substrate 4
is heated to, for example, about 500 DEG 0 using a heat source 6, and in this state, the resist film 5 is selectively irradiated with an electron beam 7 of, for example, 20 KeV so as to obtain a gate electrode pattern (dose of 100 .mu.CS).

FIG. 3 shows the process state in which the resist film after the selective irradiation is developed and the underlying phosphorous-doped polycrystalline 84 film and Si oxide film are etched away using the developed resist film 5' as a mask. FIG. 4 is obtained by removing the resist film. polycrystalline s
i Gate electrode 8, gate oxide film 9. This is a MOS capacitor formed from a Si substrate 1.

Here, the shape of the capacitor is, for example, 5008m x 500
It was set as μm.

MOS capacitors and pacitors having the same shape as those described above are formed using conventional optical lithography that does not cause damage, and using this as a standard sample, the deviation of the flat band voltage vFB, which is a material for determining the presence or absence of damage, is measured for the MOS capacitor of the above example. Upon investigation, the amount of deviation was found to be negligible within the measurement error range. On the other hand, 20 KeV was applied without heating the resist film-coated substrate.

For a MOS capacitor with the same shape as above, which was formed by selective irradiation with a 100μC/7 electron beam, the amount of deviation in VFB from the standard sample was calculated to be approximately 1°5.
■It was. From the above, it can be seen that in forming a MOS device by the method of the present invention, damage caused by high-energy electron beam irradiation can be significantly suppressed.

In the above embodiment, an example of application of the present invention to the case of forming a MOS capacitor was described, but the present invention also applies to MOS transistors, bipolar elements, distribution IP devices, etc. ? (7) It can also be applied when forming a predetermined pattern. Furthermore, the present invention can be applied to reduce damage when forming patterns using high-energy ion beams, X-rays, etc. in addition to electron beams. In addition, in the above example, the heating holding temperature was ~500°C,
It goes without saying that the value is not limited to this value and should be selected depending on the energy amount of the particle beam or X-ray, the irradiation amount, the substrate material to be treated, the particle beam/X-ray sensitive material, etc. . In addition, in specific devices for pattern formation, such as electron beam lithography equipment, ion beam lithography equipment, and Any method or arrangement may be used as long as it does not interfere with the environment. Any sensitive material may be used as long as it has heat resistance and appropriate sensitivity to particle beam and Things that exhibit sensitive characteristics at 300 to 800°C, specifically silver (Ag)... rogenide, arsenic (AS) - selenium (Se), arsenic (As) - sulfur (S), e ( Ag)-Selenium (8e), Germanium (Ge)-Selenium (S
e) type chalcogenide glass material, aluminum oxide (Aff1203), tantalum oxide (Taz
Inorganic materials such as Os) are suitable.

In addition, the method of the present invention can be modified and applied in various ways without departing from the spirit thereof.

[Brief explanation of the drawing]

1 to 4 are process sectional views for explaining one embodiment of the present invention. In the figure, 1...81 substrates, 2...
...3 i02 film, 3...polycrystalline 8i film, 4...substrate to be processed, 5.5'...resist film, 6...heat source, 7
...Electron beam, 8...Gate electrode, 9...Gate oxide film.

Claims (3)

[Claims] (1) In a method of forming a pattern on the sensitive film by selectively irradiating a particle beam or X-rays of a predetermined energy onto a sensitive film for particle beams or X-rays on a substrate to be processed and developing it, the particle beams of a predetermined energy or X
A pattern forming method characterized in that selective irradiation of the sensitive film on the substrate to be processed with a line is performed while the substrate to be processed is heated and maintained at a predetermined temperature. (2) The pattern forming method according to claim 1, wherein the sensitive film is made of a material selected from silver halide, chalcogenide glass, M2O3, or Ta 205. (3) The heating and holding temperature of the substrate to be treated during irradiation with particle beams or X-rays of a predetermined energy is 300 to soo'o
The pattern forming method according to claim 1, wherein the pattern forming method is within the range of .