JPS6170725A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To attach a photoresist film of uniform thickness to a semiconductor wafer by dropping charged ultrafine droplets from a substance to be coated, and then accelerating the charged droplets. CONSTITUTION:A droplet beam 12 of a coating agent is drawn in a pattern of a region to be coated for a stationary semiconductor wafer 5 by controlling the discharge of a discharger 1 or applying a deflecting voltage of a deflecting electrode 3. The deflection and the movement of the wafer can be combined with the drawing of the pattern. When the discharging pressure is approx. 10kg/cm, the accelerating voltage is approx. 4kV, and the agent having the viscosity up to 15cps and the surface tension of 45dyne/cm is coated, it becomes a line width of up to 30mu. To increase the drawing width, the deflection may be formed, and an AC voltage is applied to the electrode 3 to deflect in Y direction. Thus, radial irregular coating does not occur as seen in the conventional rotary coating, but substantially completely uniform agent coating can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention fabricates high density integrated circuits. The present invention relates to a method for manufacturing a semiconductor device.

Conventional Structure and Problems Conventionally, in the manufacturing method of semiconductor devices, in each step of forming a circuit pattern, a photoresist is coated on the surface of a semiconductor substrate, and a light beam corresponding to a photomask having a circuit pattern is applied. A widely used method is to form the circuit pattern on a semiconductor substrate using photoresist by exposing an image onto the photoresist and developing it. Thereafter, the portion of the semiconductor substrate that does not have the photoresist is processed by means such as etching or ion implantation. The photoresist is then removed from the semiconductor substrate, completing one step in circuit pattern formation.

The photoresist applied to the semiconductor substrate usually has a viscosity of about 10 to 60 α poise, and is made of, for example, a cinnamic acid ester resin, which is used in the form of a solution diluted with an organic solvent. An appropriate amount is dropped onto the substrate. Thereafter, the semiconductor substrate is rotated about a central axis perpendicular to the plane. As a result, the excess photoresist is blown off by centrifugal force, and the remaining portion becomes a film to be applied to the semiconductor substrate. The thickness of the coated film is determined by the viscosity of the photoresist, the rise characteristics of the rotational speed per revolution, the characteristics of the solvent to be volatilized, etc.

In this method of coating in one rotation, the thickness of the coated film also includes the characteristics of the photoresist. It varies slightly depending on the coating conditions. Therefore, the film thickness is the same on the same wafer 7.
It also changes within the arc, and in general, unique radial unevenness occurs due to centrifugal force during rotation. The unevenness in the coating film thickness caused by such coating conditions becomes a pattern that determines the resistor or coating area in various etching and ion implantation processes in subsequent steps, resulting in uneven etching or unevenness in the ion implantation area. becomes. In particular, when such unevenness occurs during the manufacturing process of a solid-state image sensor, it appears on the image plane as sensitivity unevenness and dark output unevenness corresponding to such unevenness, significantly impairing the image quality of the image.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a method for manufacturing a semiconductor device that can apply a photoresist or the like to a semiconductor wafer with a uniform thickness.

Configuring the Invention The method for manufacturing a semiconductor device of the present invention includes converting a material to be coated into electrically charged microdroplets, and then accelerating the electrically charged microdroplets.

The explanatory drawings of the embodiments show the configuration of a coating device for realizing the present invention. 1 is a discharge part for making the coating agent into a straight beam;
2 is an acceleration electrode, 3 is a deflection electrode, 4 is a shielding electrode, 5 is a semiconductor wafer, 7 is an XY feeding device for the semiconductor wafer 6, 8
is a controller that controls the spray beam consisting of minute droplets of the coating material to be coated and the semiconductor wafer to be coated. 9 is a mist beam deflection control device, and 10 is a mist guard. There are various methods for the coating agent discharge section 1, including a continuous jet generated by applying high pressure to the coating agent [a continuous jet type that generates micro droplets that fly by applying vibrations, and a continuous jet type that generates micro droplets that fly by applying vibrations, , a method that electrostatically sucks and draws out the coating agent from the discharge section 1, and a method called an on-demand type that applies pressure to the coating agent in the discharge section 1 and discharges it only when necessary. There is also.

In the coating method according to the present invention, the droplet beam is only continuously flown in a straight line, and the coating area of the wafer to be coated is uniformly moved by moving the mounting stage 7 in the X direction and the Y direction. It is possible to fill it in. However, by controlling the ejection of the droplet beam 13 of the coating agent by the ejection unit 1 or applying a deflection voltage by the deflection electrode 3, it is also possible to draw a pattern of the area to be coated on the stationary semiconductor wafer 6. Furthermore, the drawing of these patterns can be performed in combination with deflection and movement of the wafer. With a discharge pressure of about f10kqlα and an acceleration voltage of about 4KV, ~
When applied with a coating agent having a viscosity of 16 CpS and a surface tension of 46 dyne/α, the line width is ~3o microns. To increase the drawing width, deflection is applied (apply an AC voltage to the deflection electrode to deflect it in the Y direction.The value is determined by taking into consideration the deflection amplitude, X feed, etc., but the above Since the response of the droplet beam 13 up to about 10 KHz can be obtained under these conditions, the range of setting the five conditions is wide.

Effects of the Invention According to the method of the present invention detailed above, the radial coating unevenness that occurs in conventional spin coating does not occur, and the material to be coated can be applied completely uniformly. .

Therefore, it is extremely effective in the process of manufacturing devices in fields where two-dimensional uniformity is strictly required in terms of characteristics, such as solid-state imaging devices and field-effect light-emitting devices. Furthermore, it becomes possible to easily draw a two-dimensional pattern of the coated film, which is often useful as it provides a new means for processing semiconductors.

[Brief explanation of the drawing]

The figure is a configuration diagram of a coating device for realizing the present invention. DESCRIPTION OF SYMBOLS 1... Coating agent discharge part, 2... Accelerating electrode for coating agent droplets, 3... Deflection electrode for coating agent droplet beam, 4...... Shielding electrode, 5... Semiconductor wafer to be coated, 6... Coating agent feed pump, 7
...XY moving stage, 8...Control device, 9...Deflection control device %1o...Mist guard.

Claims (2)

[Claims] (1) A method for manufacturing a semiconductor device, characterized in that a material to be coated is made into charged droplets, and the charged droplets are accelerated and coated on one surface of a semiconductor substrate. (2) A method for manufacturing a semiconductor device according to claim 1, characterized in that the accelerated coating material droplet particle beam is deflected by an electric field and the coating area is controlled by movement of the semiconductor substrate.