JPS6182432A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To eliminate an undeveloped portion or an insufficient developed portion by attracting and holding a semiconductor wafer to a rotary head, dropping a solution on the wafer to alternately rotate normally and reversely the wafer at a low speed to treat it with the solution. CONSTITUTION:After a rotary head 1 is raised to attracted and hold a semiconductor wafer 4 having an exposed positive type photoresist film, the head 1 is moved down. Then, a developer 10 is dropped from a nozzle 9 on the wafer 4 which is rotating at a low speed to spread the developer 10 by a centrifugal force on the entire upper surface of the wafer 4. The wafer is rotated at a low speed of 100rpm or lower for 1-10sec in the state the prescribed amount of the developer 10 is held on the wafer 4 in a direction of an arrow with a solid line, similarly rotated in a direction of an arrow with a broken line, and this operation is performed in several cycles. The developer 10 continues to stop by the inertia, a relative speed variation occurs to the wafer 4, and adheres to the entire upper surface of the wafer 4, thereby uniformly developing it.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a semiconductor device, and is particularly useful for, for example, developing a positive resist using a semi-day or lip method.

2. Description of the Related Art When manufacturing a semiconductor device, there is a step of patterning an insulating film such as an oxide film or a conductive film such as an aluminum deposited film. In this patterning process, a 7-photoresist film is generally formed on the surface of a semiconductor wafer, a mask with a predetermined pattern is overlaid and exposed, and then developed and unnecessary parts are dissolved and removed to form a window hole. This is done by etching away the exposed insulating film and conductive film. In some cases, an insulating film or a conductive film is formed on top of the photoresist film with the window hole formed in the same manner as above, and the photoresist film is dissolved with a solvent, and then the insulating film or conductive film is formed on top of the photoresist film. In some cases, patterning is performed by a so-called lift-off method in which the pattern is removed at the same time.

The development process for the photoresist film described above includes the sea urchin development method that uses a developer solution and the dry development method that uses gas plasma.Currently, the sea urchin development method is mainly used due to cost considerations. has been done.

Wet development methods include: ■ The dip method in which a large number of exposed semiconductor wafers are stored in a carrier made of Teflon (registered trademark) and immersed in a developing solution; The shower method involves fixing a plurality of carriers at equal intervals along the periphery of a turntable, and spraying the developer in a radial direction from a nozzle placed at the center of rotation while rotating the turntable at high speed. (2) There is a spray method in which a semiconductor wafer is held by suction in a rotating head and rotated at high speed, and a developer is sprayed onto the semiconductor wafer. However, these methods (1) to (2) all use a large amount of developer, which has the disadvantage that not only the cost of materials increases, but also the cost of treating waste liquid.

On the other hand, with the recent demand for fine patterns, it has become necessary to prevent dust from adhering or to suppress dimensional variations due to variation in development rate within the wafer surface as much as possible.

Therefore ■ Rotating a single semiconductor wafer 1. A semi-dip method (or paddle method) has been considered in which the semiconductor wafer is held by suction on a semiconductor wafer, and the current liquid is dropped onto the semiconductor wafer, spread over the entire surface, and then held for a predetermined period of time (methods ①, ②, and ② above). (Japanese Unexamined Patent Publication No. 59-132620).

Hereinafter, with reference to Figures 2 to 5, the above-mentioned semi-day
A developing method using the whelk method will be explained.

In FIG. 2, reference numeral 1 denotes a rotary hood, a shaft 2 is fixed at the center of its lower surface, it is configured to be rotatable in a predetermined direction by a motor 3, and configured to be movable up and down by a motor (not shown), and a vacuum The system is configured to be able to attract and hold the semiconductor wafer 4. Reference numeral 5 denotes a barrel in which the rotating helioid 1 is received, and has a side wall 6 and a bottom plate 7;
The bottom plate 7 has a discharge port 8.

In the above configuration, as it rotates, the hand 1 is raised to adsorb and hold the semiconductor wafer 4 on which the photoresist film (not shown) has been exposed, and is lowered into the cup 5 as shown in FIG. Afterwards, the developer 10 is dropped from the nozzle /I/9, and the developer IO is spread over the entire surface of the semiconductor wafer 4. This developing solution 10 is applied to the semiconductor wafer 4 by surface tension, as shown in FIG. 3, by keeping the rotary lid 1 stationary or rotating at a low speed for a predetermined period of time for development. When the development is completed, as shown in FIG. 4, the rotor 1 is rotated at high speed to shake the developer 10 on the semiconductor wafer 4 by centrifugal force, and remove the nozzle from above.
The rinsing liquid 12 is sprayed through the vll to perform rinsing treatment, and the waste liquid 13 is discharged from the discharge port 8. Thereafter, the semiconductor wafer 4 is dried by high-speed centrifugal drying or the like.

Problems to be Solved by the Invention According to the above-mentioned semi-dip method, only the minimum necessary amount of developer is used, which not only reduces material costs, but also makes it relatively easy to control pattern dimensions and prevents dust from adhering. It has the advantage of being small.

However, as shown in FIG. 5, in the semiconductor wafer 4 after development, undeveloped portions or underdeveloped portions 14 may occur locally.

Means for Solving the Problems This invention provides the undeveloped portion or the insufficiently developed portion f+14.
The main objective is to eliminate this process, and it involves a process of suctioning and holding a semiconductor wafer on a rotating head, a process of dropping a processing liquid onto the semiconductor wafer, and a process of alternately rotating the semiconductor wafer forward and backward at low speed. The method is characterized in that it includes a step of performing liquid treatment.

The processing solution is typically a developer, more specifically a developer for positive photoresist films.

Effect According to the above means, when switching the direction of transfer to the semiconductor wafer, stress due to inertia acts between the semiconductor wafer and the processing solution, causing the processing solution to flow on the semiconductor wafer, and the concentration distribution is changed. As the process becomes more uniform and the semiconductor wafer is more easily wetted by the process liquid, there are no areas where the process liquid does not adhere, and there are no local unprocessed areas or under-processed areas, and uniform processing can be performed.

EXAMPLE Hereinafter, an example method according to the present invention will be explained in the case of development processing with reference to the drawings.

FIG. 1 shows a sectional view of a manufacturing apparatus used in the present invention. The figure is the same as FIG. 3 except for the following points, and the same parts are given the same reference numerals and their explanations will be omitted. The difference from FIG. 3 is that the motor 15 that rotates the rotary head 1 is a reversible motor capable of forward and reverse rotation.

Using the above-mentioned apparatus, first, the rotating hood 1 is raised to suction and hold the semiconductor wafer 4 provided with the exposed Bong-type photoresist film, and then the rotating hood 1 is raised as shown in FIG. Force, lower into the tube 5. Next, the motor 15 is driven to drop the developing solution 10 from the nozzle V 9 onto the semiconductor wafer 4 which is rotating at a low speed of about 10 to 100 rpm. Spread over the entire top surface of the semiconductor wae/%4. Alternatively, a predetermined amount of developer 1 is placed on the semiconductor wafer 4 in a stationary state.
After dropping 0, the semiconductor wafer 14 may be rotated at low speed in the same manner as above to spread the developer 10.

After this, as shown in FIG. 1, with a predetermined amount of developer 10 held on the semiconductor wafer 4, the semiconductor wafer 4 is rotated at a low speed of 100 rpm or less for 1 to 10 seconds in the direction of the solid line arrow, and then rotated in the direction of the solid line arrow for 1 to 10 seconds. direction for 1 to 10 seconds at the same low speed, and repeat this operation for several cycles. Then, when the rotation direction of the semiconductor wafer 4 is switched, the semiconductor wafer 4 stops rotating in the forward and reverse directions, and the developer 10 above it tries to continue rotating due to inertia, while the semiconductor uni/14 rotates in the opposite direction. When the developer 10 starts rotating, it tends to continue to stop due to inertia, and a relative speed change occurs between the developer 10 and the semiconductor wafer 4, and the developer 10 flows over the semiconductor wafer 4. As a result, when the developer 10 is spread by centrifugal force, even if there is a portion that does not adhere to the semiconductor wafer 714, the developer 10 adheres to the entire upper surface of the semiconductor wafer 4, and uniform development processing is performed. Next, as in FIG. 4, the semiconductor wafer 4 is rotated at a high speed of about 500 to 1000 rpm, the developer 10 on the semiconductor wafer 4 is shaken off by centrifugal force, and then the nozzle /v11 or the larynce 1lff is spun.
The developer solution 1 on the semiconductor wafer 4 is sprayed with
0 is washed away, and the semiconductor wafer 4 is further dried by high-speed centrifugal drying at 3000 to 5000 rpm.

Thus, according to the present invention, undeveloped areas and underdeveloped areas 14 as shown in FIG. 5 do not occur.

In the above embodiments, the case where a positive photoresist, c)ll is developed, is described, but it is also possible to carry out liquid processing such as etching and peeling off a photoresist film.

Effects of the Invention According to the present invention, a semiconductor wafer can be subjected to liquid processing using a small amount of processing liquid, and local unprocessed areas or under-processed areas do not occur.

[Brief explanation of the drawing]

FIG. 1 shows a cross-sectional view of the present invention during development of a positive photoresist film. ' Figures 2 to 4 show the conventional semi-dilib ring.
FIG. 4 is a cross-sectional view of different stages for explaining the imaging method. FIG. 5 is a plan view of a semiconductor wafer showing a raw material failure state in a conventional method. 1...... To rotation, sodo, 2...
・・・・・・・・・ Axis, 4・・・・・・・・・・・・ Semiconductor wafer, 5...
...Four...Cup, 10...Processing solution (developer), 15...
...Reversible rotary motor.

Claims (1)

[Claims] 1. A step of suctioning and holding a semiconductor wafer on a rotating head, a step of dropping a processing liquid onto the semiconductor wafer, and a step of processing the semiconductor wafer with the liquid while alternately rotating forward and backward at low speed. A method for manufacturing a semiconductor device, comprising the step of: 2. The method of manufacturing a semiconductor device according to claim 1, wherein the step of dropping the treatment liquid is performed while rotating the semiconductor wafer at a low speed.