JP2010232498A5 - Etching method, etching apparatus, and substrate - Google Patents

Description

The present invention relates to an etching method and an etching apparatus for etching an etching agent supplied from an etching nozzle toward the surface of a workpiece. The invention further relates to an etched substrate.

FIG. 11B shows a modification of the etching nozzle of FIG. The nozzle 17 includes a plurality of inner tubes 18 arranged continuously in a horizontal row and one outer tube 19 arranged so as to surround them. An etchant is supplied to the surface of the workpiece from the inner opening 20 of each inner tube 18 to etch the surface in a laterally elongated manner from an outer opening 21 defined between the inner tube and the outer tube 19. It is collected by suction. The nozzles 11 and 17 in FIGS. 11A and 11B are moved in a direction perpendicular to the arrangement direction of the nozzles 12 or the inner pipes 18 so that a wide area on the surface of the workpiece is obtained by one scan. Can be processed at once.

As shown in FIG. 12B, the nozzle 28 can be configured such that the lateral dimension of the outer opening 32 is somewhat wider than the lateral dimension of the workpiece 33. In this case, as indicated by an arrow in the figure, the surface of the workpiece 33 is uniformly processed over the entire width in one scan by moving the nozzle 28 in a direction orthogonal to the lateral direction. Can do.

The processing depth of the workpiece may change along a direction orthogonal to the moving direction of the etching nozzle. For example, when the surface of the workpiece is inclined in a direction perpendicular to the moving direction of the nozzle, such as a wafer having a thickness gradient, it may be required to process the inclined surface horizontally. In addition, the polished wafer tends to be thicker at the peripheral edge than the inner part. In such a case, it is necessary to delete the peripheral edge more and process the whole to a uniform thickness.

In such a case, if the spatial resolution of the etching nozzle, particularly the resolution in the direction orthogonal to the moving direction of the nozzle is sufficiently increased, the workpiece surface can be similarly processed into a desired profile. For this purpose, for example, the etching nozzle 1 of FIG. 10 may have a sufficiently small inner diameter of the outer tube 3, that is, an outer diameter of the outer opening 5. However, if the resolution in the direction orthogonal to the nozzle movement direction is increased, the feed pitch in the direction orthogonal to the nozzle movement direction is reduced accordingly, and the number of scans is increased, resulting in increased man-hours and reduced work efficiency and productivity. To do.

In the etching nozzles 17 and 28 of FIG. 11B and FIG. 12, the lateral dimensions of the outer openings 21 and 32 are large, and the depth of the processing mark is constant over the entire range . If an inclined surface is to be processed horizontally with such a nozzle, the feed pitch in the direction orthogonal to the moving direction of the nozzle must be reduced in accordance with the inclination, and scanning must be repeated repeatedly. As a result, the number of scans of the nozzle is extremely increased, man-hours are increased, work efficiency and productivity are lowered, and advanced technology and a control device for accurately and accurately controlling nozzle scanning are required. Become.

The etching nozzles 11 and 22 in FIGS. 11A and 11C adjust the flow rate and / or the temperature of the etching agent supplied to each nozzle unit along the lateral direction , thereby adjusting the lateral direction of the etching nozzle . It is possible to change the machining depth within a range of dimensions . However, in order to increase the processing accuracy, the tube diameter of the single nozzle must be made thinner, and in order to process a larger area, the number of single nozzles must be increased. Such an etching nozzle has a problem that the structure is complicated and the cost is high. Furthermore, in order to adjust the etching agent flow rate and the temperature of each nozzle unit with high accuracy while moving the entire etching nozzle, a very advanced control technique is required.

Therefore, the present invention has been made in view of the above-described conventional problems, and its purpose is to simultaneously supply and collect an etching agent on the surface of a workpiece, particularly as in the local wet etching method. using an etching nozzle for have a double pipe structure suitable for use in wet etching, the desired profile of the surface of the workpiece, a small number as possible, preferably in one scan with different profiles It is another object of the present invention to provide an etching method that can be efficiently processed.

Another object of the present invention is to provide an etching apparatus that includes such an etching nozzle and can efficiently process the surface of a workpiece into a desired profile by wet etching.
Furthermore, the objective of this invention is providing the board | substrate processed into the desired profile by utilizing those etching methods and / or apparatuses.

The etching method of the present invention, in order to achieve the above object, comprises an inner tube having an inner opening and an outer tube defining an outer opening between the disposed outside of the inner tube inner tube, the outer Preparing an etching nozzle in which the dimension in the width direction of the opening is not constant in a direction perpendicular to the width direction;
The inner opening and the outer opening of the etching nozzle is opposed to the surface of the workpiece, while supplying et etching agent from the inner opening to the workpiece surface, while sucking recover from the outer opening, and etching the nozzle and the workpiece Moving at least one of them in the width direction of the outer opening;
It is characterized by including .

By preparing and using the etching nozzle in this way, the processed cross-sectional shape of the workpiece by etching can be determined by the outer peripheral shape of the outer opening of the etching nozzle . For example, when the difference between the cross-sectional profile before processing the workpiece and the target cross-sectional profile is used as the processing profile, the width dimension of the outer peripheral edge shape of the outer opening of the etching nozzle corresponding to the change in the processing profile Can be changed along the direction perpendicular to the width direction to etch the surface of the workpiece. Thus, according to the etching method of the present invention, the surface of a workpiece having various cross-sectional profiles can be efficiently formed into a desired profile , preferably with a single scan of the etching nozzle or with a smaller number of scans. Can be processed.

In one embodiment , the etching nozzle has a linearly changing dimension in the width direction of the outer opening along a direction perpendicular to the width direction . As a result, when the machining profile of the workpiece is uniformly inclined along the direction orthogonal to the width direction , the workpiece surface can be efficiently machined into a desired profile with fewer scans. it can.

In another embodiment, the etching nozzle is partially changed along a direction in which the width dimension of the outer opening is perpendicular to the width direction. As a result, when the machining profile of the workpiece is partially changed within the range of dimensions in the direction perpendicular to the width direction of the outer opening of the etching nozzle, the workpiece surface is made to correspond to the change. A desired profile can be efficiently processed with a small number of scans.

In yet another embodiment, the etching nozzle, at least near one end in the direction orthogonal to the width direction of the outside opening, vary along the direction in which the width dimension of the outer opening is orthogonal to the width direction Yes . This is especially advantageous when the peripheral edge of the workpiece is thicker than the inner part, such as a polished wafer, and the workpiece surface is also desired with fewer scans. It is possible to efficiently process the profile.

In one embodiment, in the step of moving at least one of the etching nozzle and the workpiece, at least one of them moves linearly. As a result, a workpiece such as a rectangular wafer having a thickness gradient can be efficiently processed along the edge direction.

In another embodiment, in the step of moving at least one of the etching nozzle and the workpiece, at least one of them moves in the circumferential direction. As a result, a workpiece such as a circular wafer can be efficiently processed along the circumferential direction.

According to another aspect of the present invention, there is provided a substrate processed by the above-described etching method of the present invention. This substrate is processed into a desired profile.

In yet another aspect, an etching apparatus of the present invention includes an etching nozzle described in relation to the above-described etching method of the present invention,
Supply means for supplying an etchant to the inner tube of the etching nozzle;
A recovery means for recovering the etching agent from the outer tube of the etching nozzle;
A moving means for moving at least one of the etching nozzle and the workpiece while maintaining a distance between the etching nozzle and the workpiece;
A reservoir for storing an etchant supplied to the inner tube of the etching nozzle and recovered from the outer tube;
Means for maintaining the reservoir etchant at a desired temperature;
It is characterized by providing. Accordingly, the surface of the workpiece having various profiles can be efficiently processed into a desired profile while adjusting and controlling the temperature of the etching agent supplied to the surface of the workpiece by wet etching.

Some embodiments further comprise means for circulating the etchant stored in the reservoir to the inner tube. Thereby, while reducing the usage-amount of an etching agent and reducing processing cost, the influence which an etching agent can have on an environment can be suppressed.

In this embodiment, the direction along the moving direction A of the etching nozzle 41 is the first direction, and the direction orthogonal to the direction is the second direction. The outer opening 45 is elongated in the left-right direction, that is, the second direction in the drawing, and the dimension L in the first direction , that is , the dimension in the width direction changes linearly along the second direction over the entire range . The etching nozzle 41 has the inner opening 44 and the outer opening 45 opposed to the surface of the workpiece 48, and the direction perpendicular to the horizontal center line of the outer opening coincides with the movement direction A, that is, the first direction. Deploy.

FIG. 2 schematically shows the configuration of an embodiment of an etching apparatus according to the present invention. The etching apparatus 51 of this embodiment includes the etching nozzle 41 shown in FIGS. 1A and 1B and a reservoir 53 for storing the etching solution 52. The reservoir 53 is connected to the recovery passage 47 of the etching nozzle 41 by a pipe line 54. By reducing the pressure in the reservoir 53 with the suction pump 54, the etching solution after processing the workpiece surface 48 a can be sucked from the outer opening 45 through the collection passage 47 and collected in the reservoir. At this time, the etching nozzle 41 is held so that the inner opening 44 and the outer opening 45 keep a distance from the surface 48a of the workpiece, as shown.

The etching apparatus 51 includes moving means (not shown) for moving the etching nozzle 41 relative to the workpiece 48. In one embodiment, the moving means can move the etching nozzle 41 linearly or circumferentially, or move it in the XY directions orthogonal to each other to process a large area. In another embodiment, the moving means can move or rotate the workpiece 48 linearly, or can be fixed to an XY table or the like and moved in the orthogonal XY directions. In another embodiment, the etching nozzle 41 can be moved in the X direction, and the workpiece 48 can be moved in the Y direction orthogonal thereto. The moving means can maintain a distance between the inner opening 44 and the outer opening 45 of the etching nozzle 41 and the surface 48a of the workpiece.

Each point on the workpiece surface 48a is exposed to the etchant while the point is within the range of the outer peripheral edge of the outer opening 45 of the nozzle on the plane. As described above, the outer peripheral edge of the outer opening 45 has an isosceles trapezoidal shape, and the dimension L in the first direction changes linearly along the second direction over the entire range in the second direction. Since the etching amount is proportional to the integrated amount of time that the surface of the workpiece is exposed to the etching agent, each point on the surface of the workpiece is exposed to the etching agent in proportion to the dimension L in the first direction. Becomes longer and the amount of etching process increases. Therefore, the inclination of the machining groove bottom surface 62a is determined by the inclination of the change in the dimension L in the first direction of the outer opening.

When reaching the upper end of the wafer, the etching nozzle 41 is moved to the right in the figure in the Y direction. The feed amount in the Y direction is determined by the maximum dimension in the second direction of the outer opening 43 of the nozzle. Further, the nozzle is moved linearly from the upper end to the lower end of the wafer 63 at a constant speed parallel to the processing groove 65. When the nozzle reaches the lower end of the wafer, it is moved to the right in the figure in the Y direction with the same feed amount. Then, the wafer is linearly moved from the lower end to the upper end at a constant speed. In this way, the target cross-sectional profile 64 can be formed on the wafer 63 by supplying the etching solution and etching the surface while scanning the entire surface of the wafer surface 63 a to be processed by the etching nozzle 41.

The etching nozzle 71 of the second embodiment is suitable, for example, for flatly etching the entire surface that is flat along the second direction and that is flat at the left and right sides, and is raised. As described above, the quartz wafer after polishing is thicker in the vicinity of the edge than the inner part. 7 (A) and 7 (B) show a wafer 80 having a cross-sectional shape in which the inner portion is flat and the vicinity of the right and left edges is inclined and becomes high, and the entire surface 80a is flat and the whole wafer is platen. The point of processing to make the thickness uniform is shown. Here, as shown in FIG. 7A, the difference between the cross-sectional profile of the surface 80a before processing and the target cross-sectional profile that is a flat surface indicated by the imaginary line 81 is the processing profile. In this embodiment, the machining profile has a shape obtained by vertically inverting the cross-sectional shape of the machining groove 79 shown in FIG.

FIG. 7B is a view of the surface 80a of the wafer 80 arranged horizontally as viewed from below. As can be seen from the figure, the etching nozzle 71 has a width in the second direction of the outer opening 75 that is slightly larger than the width of the wafer 80 and is within the range of the dimension in the second direction of the outer opening . Arrange to fit. While moving the etching nozzle 71 from the lower end of the wafer 80 toward the upper end in a straight line at a constant speed, the etching liquid is supplied to etch the wafer surface 80a.

The outer opening 75 of the nozzle matches the position of the central portion where the dimension L in the first direction is constant and the dimension in the second direction with the flat inner portion of the wafer 80, and from the central portion to the left and right ends. An outer peripheral shape is formed such that the inclination of the change in the dimension L in the first direction corresponds to the inclination near the left and right edges of the wafer. Thereby, the surface 80a of the wafer 80 can be processed into a target flat surface by one scanning of the etching nozzle 71.

Claims (8)

An inner tube having an inner opening; and an outer tube disposed outside the inner tube and defining an outer opening between the inner tube and a dimension in a width direction of the outer opening being orthogonal to the width direction. Preparing an etching nozzle that is not constant in the direction;
Wherein the inner opening and the outer opening of the etching nozzle to face the surface of the workpiece, while sucking recover from the outer opening while supplying to said workpiece surface et etching agent from the inner opening, said etch Moving at least one of the nozzle and the workpiece in the width direction;
An etching method comprising : The etching nozzle, etching method of claim 1, wherein said width dimension of said outer opening is linearly changed along the direction perpendicular to the width direction. The etching nozzle, etching method of claim 1, wherein said width dimension of said outer opening is partially changed along a direction perpendicular to the width direction. The etching nozzle, at least one end near the portion in the direction perpendicular to the width direction of the outer opening, said width dimension of the outer opening is changed along a direction perpendicular to the width direction The etching method according to claim 3. 5. The etching method according to claim 1, wherein in the moving step, at least one of the etching nozzle and the workpiece is moved linearly. 5. The etching method according to claim 1, wherein in the moving step, at least one of the etching nozzle and the workpiece is moved in a circumferential direction. 6. A substrate processed by the etching method according to claim 1. And etching nozzle according to any one of 請 Motomeko 1 to 4,
Supply means for supplying an etchant to the inner tube of the etching nozzle;
Recovery means for recovering an etchant from the outer tube of the etching nozzle;
A moving means for moving said at least one of an etching nozzle and the workpiece, while keeping the distance between the workpiece and the etching nozzle,
A reservoir for storing the etchant supplied to and recovered from the outer tube of the etching nozzle;
Means for maintaining the reservoir etchant at a desired temperature;
An etching apparatus comprising: