KR100492533B1 - Fabrication method of multi-step structure using anisotropic etching and multi-step structure - Google Patents

Abstract

The present invention provides a method for manufacturing a multi-stage structure and a multi-stage structure, comprising: a mask applying step of masking a plurality of slits having a gap on a silicon substrate; Etching the substrate masked in the mask applying step by an anisotropic plasma etching method; A mask cleaning step of cleaning the mask on the substrate etched in the etching step; A barrier rib removing step of removing barrier ribs between the slits by isotropic etching of the substrate cleaned in the mask cleaning step; By providing a multi-stage structure manufacturing method using the anisotropic etching, and the multi-stage structure manufactured thereby, comprising a configuration, including, to reduce the manufacturing cost and reduce the manufacturing error by reducing the process.

Description

Multi-Stage Structure Manufacturing Method Using Anisotropic Etching and Multi-Stage Structure {FABRICATION METHOD OF MULTI-STEP STRUCTURE USING ANISOTROPIC ETCHING AND MULTI-STEP STRUCTURE}

The present invention relates to a multi-stage structure manufacturing method using anisotropic etching and to a multi-stage structure manufactured by the above method, and in particular, a method for manufacturing a multi-stage structure using the loading effect of the anisotropic etching and produced by Relates to a multilevel structure.

The multi-level structure refers to a structure having a plurality of stages or inclined surfaces, such as a slider, a silicon binary optical micro lens, a micro lens, and the like.

Sliders are the core components of many types of information storage devices, including hard disk drives, which allow the head or pick-up to rise stably at a constant height on a disc-shaped recording medium that rotates at a high speed. It helps to perform I / O. The slider lands on the surface of the disk when the recording medium disk is stopped, and when the disk starts to rotate, the slider is injured by the flow of air generated by the rotation. Therefore, in order for the slider to obtain an initial flotation force when the disc starts to rotate, an inclined taper with a small angle of several milli radians is needed on the leading edge side of the slider. This requires an air-bearing surface on the side facing the recording medium.

Conventionally, in order to form such a taper and air bearing surface, machining methods such as polishing individual slider surfaces have been used. This method not only has a problem of poor reproducibility, but also individual processing of the slider and the number of unit processes. Due to the increase in manufacturing costs, there are disadvantages such as a decrease in mass production.

Silicon binary optical microlenses (binary optic microlenses) are widely used to improve the performance of infrared sensors or infrared imagers, and have a multi-stage configuration. The silicon binary optical microlenses have excellent optical performance as the number of stages increases. In order to form four stages, m-1 alignments were performed using m photomasks. Therefore, since a plurality of photomasks are formed and etched, not only the process takes a long time but also a loss of optical performance occurs due to accumulation of errors in the alignment process.

A conventional method of manufacturing a micro lens is a method of using a spherical surface formed by surface tension as a lens, or forming a mold by isotropic etching or the like to take out a lens. However, this method has a problem that only the production of spherical lenses is possible due to the characteristics of the manufacturing method.

The present invention has been made to solve the above problems, to produce a multi-stage structure using only one photomask, to reduce the manufacturing cost by reducing the process, and to produce a multi-stage structure using anisotropic etching to reduce the manufacturing error It is an object of the present invention to provide a method and a multilevel structure manufactured by the method.

The present invention provides a mask coating step of masking a plurality of slits of varying spacing on a silicon substrate in order to achieve the above object; Etching the substrate masked in the mask applying step by an anisotropic plasma etching method; A mask cleaning step of cleaning the mask on the substrate etched in the etching step; A barrier rib removing step of removing barrier ribs between the slits by isotropic etching of the substrate cleaned in the mask cleaning step; It provides a multi-step structure manufacturing method using anisotropic etching, characterized in that configured to include.

In addition, the substrate is a silicon substrate, the anisotropic etching method in the etching step uses an anisotropic plasma etching method, the isotropic etching in the barrier rib removing step is preferably used an isotropic plasma etching method.

In addition, in the mask coating step, in order to manufacture an air-floating slider having a taper and an air bearing surface, a mask is applied on the silicon substrate on which the upwardly inclined taper of the air-floating slider is formed so that the interval between slits becomes narrower. On the silicon substrate on which the upper end of the air bearing surface is formed, the interval of the slit is constant and the mask is applied narrowly, and on the silicon substrate on which the lower end of the air bearing surface is formed, the interval of the slit is preferable and the mask is applied widely. Do.

On the other hand, in the mask coating step, in order to fabricate a silicon binary optical microlens composed of a plurality of stages, a mask is applied on a silicon substrate on which a stage located below is formed with a wide interval of slit, and a silicon substrate on which a stage located above is formed. It can be implemented to mask-coating the interval between the slits on the narrow.

On the other hand, the mask coating step is to form a microlens mold having an aspherical lens shape consisting of a plurality of stages, the mask is applied to a wider interval between the slits on the silicon substrate on which the lower stage is formed, the upper stage is formed On the silicon substrate, it can be implemented to apply a mask to narrow the gap between the slits.

In addition, the present invention provides a mask coating step of masking a plurality of slits of varying intervals on a silicon substrate in order to achieve the above object; Etching the silicon substrate masked in the mask applying step by an anisotropic plasma etching method; A mask cleaning step of cleaning the mask of the silicon substrate etched in the etching step; The silicon substrate cleaned in the mask cleaning step is heated in a heating furnace in an oxygen atmosphere to form a silicon oxide film on the surface of the silicon substrate ( Forming a silicon oxide film; A barrier rib removing step of removing the barrier rib between the slits by etching the silicon substrate on which the silicon oxide layer is formed in the silicon oxide layer etchant in the silicon oxide layer forming step; It provides a multi-step structure manufacturing method using anisotropic etching, characterized in that configured to include.

In addition, the present invention provides a multi-level structure using anisotropic etching produced by the multi-step structure manufacturing method.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

However, in describing the present invention, a detailed description of known functions or configurations will be omitted in order not to disturb the gist of the present invention.

1A to 1D illustrate a method of fabricating a multi-step structure using anisotropic etching according to an embodiment of the present invention, in which FIG. 1A is a cross-sectional view of a mask coated on a substrate, and FIG. 1B is a substrate etched. 1C is a cross-sectional view of an oxide film formed on the surface of the substrate, and FIG. 1D is a cross-sectional view of a completed structure after the partition wall is removed.

1A is a cross-sectional view of a state where a mask is applied onto a substrate.

As shown, the material 15 to be an etch mask is applied on the surface of the substrate 11 and then patterned to form the slits 16A-C by a photolithography process. The slits 16A-C are variously patterned according to the shape of the stages formed such as the slits 16A having a wide interval and the slits 16C having a narrow interval. The substrate 11 is preferably a silicon substrate. However, various materials such as glass, gallium arsenide, etc. may be used, and in the case of producing an optical lens, a material having excellent optical properties may be used. The mask material 15 may be formed of various materials such as a photo resistor.

1B is a cross-sectional view of the substrate being etched.

After the mask 15 is applied to the substrate 11 as shown in FIG. 1A, the exposed portion of the substrate is etched by the anisotropic etching method to form a shape as illustrated in FIG. 1B. When the silicon substrate is used as the substrate 11, the anisotropic etching method is preferably an anisotropic plasma etching method.

When the silicon substrate 11 is etched by the anisotropic plasma etching method, the etching proceeds more deeply in the slit 16A having a wider gap due to the loading effect, and shallower in the slit 16C having a narrower gap. Etching proceeds. 1B, the etching proceeds at the portion where the narrowest slit 16C is constantly formed, and the top end 12C is formed, and the etching proceeds at the portion where the slit 16B having a medium interval is constant. The intermediate end 12B is formed, and in the part where the slit 16A with the largest space | interval is formed uniformly, etching progresses and the lowest end 12A is formed. In addition, the substrate 11 positioned on the lower surface of the portion to which the mask 15 is applied is not etched, and a diaphragm 14 is formed.

After the etching is completed, the mask 15 is cleaned.

1C is a cross-sectional view of an oxide film formed on a substrate surface.

When the etched silicon substrate 11 is heated in a furnace of an oxygen atmosphere, a silicon oxide film ( 13 is formed.

The silicon oxide film 13 formed on the surface of the silicon substrate 11 is etched using an oxide film etchant to remove the partition 14 formed on the substrate 11. The oxide etching solution is generally known as a material such as a buffered oxide etch (BOE).

In the above method, the barrier rib 14 is removed after the silicon oxide layer 13 is formed. In addition, the barrier rib may be removed by isotropic etching.

1D is a cross sectional view of a multi-level structure using anisotropic etching.

As shown, a silicon substrate having three steps 12A-C having steps is formed.

As described above, the present invention can form a multi-level structure using a single photomask, thereby significantly reducing the process and reducing the process error.

Figures 2 to 4 show the structure of the slide manufactured by the manufacturing method of the present invention, Figure 2 is a perspective view of the slider, Figure 3a is a side view of the slide in an etched state, Figure 3b is a state in which the partition is removed 4 is a perspective view showing that the slide of FIG. 2 is formed on a silicon substrate.

Sliders are the core components of many types of information storage devices, including hard disk drives, which allow the head or pick-up to rise stably at a constant height on a disc-shaped recording medium that rotates at a high speed. It helps to perform I / O. The slider lands on the surface of the disk when the recording medium disk is stopped, and when the disk starts to rotate, the slider is injured by the flow of air generated by the rotation. Therefore, in order for the slider to obtain an initial flotation force when the disc starts to rotate, an inclined taper with a small angle of several milli radians is needed on the leading edge side of the slider. This requires an air-bearing surface on the side facing the recording medium.

As shown in FIG. 2, the slider 20 according to an embodiment of the present invention has a rectangular plate shape having a leading edge 30, a siding edge 31, and a tailing edge 32. A slider main body, a taper 27 having a constant inclined surface formed on the upper surface 29 of the main body 29 for the floating of the slider 20, and a protrusion 28 protruding from the upper surface 29 of the main body for stable floating. It is configured to include.

The air bearing surface is composed of the taper 27, the protrusion 28 and the upper surface 29. These air bearing surfaces can be configured in various ways depending on the required performance of the slider. In addition, the slider 20 shown is only one embodiment, and various types of sliders are known. The present invention is not only applied to the production method of the slider shown, it can be used for the manufacture of sliders of all shapes having a slope and a step.

Hereinafter, a method of manufacturing the slider shown in FIG. 2 will be described.

The manufacturing method of the slider is the same as the manufacturing method of the multi-stage structure shown in FIG. However, it is possible to manufacture the desired shape by adjusting the interval of the slit masked differently according to the shape.

As shown in Fig. 3A, in order to form the upwardly inclined surface 22A of the taper 27, the mask is sequentially applied so that the gaps 26A to 26B of the slit are narrowed, and the taper 27 forming the upper end is formed. The plane 22B and the protrusions 28 apply a mask so that the gap between the slits is constant and the gap 26C is formed, and the upper surface 29 of the main body on which the lower end is formed has a constant gap between the slits 26D. Apply a mask to form a wide.

The etching step except for the mask coating step, the mask cleaning step, the oxide film forming step, and the barrier rib removing step are the same as the method of manufacturing the multi-step structure shown in FIG.

Figure 3b is a side view of the slider is manufactured after the partition removal step. As shown, a slider composed of a taper 27 and an upper surface 29 is formed on the substrate 21.

4 is a perspective view showing that the slide of FIG. 2 is formed on a silicon substrate.

As shown in the drawing, a plurality of sliders 20 are formed on a single silicon wafer 1, and then a dicing method of dividing a general semiconductor integrated circuit device into chip units is used. Using the etching method through the etching method to separate the individual slider (20).

As described above, the present invention can form the taper of the slider and the air bearing surface with one mask coating, thereby reducing the process and reducing the process error.

In addition, since a plurality of sliders can be produced simultaneously on a single silicon wafer, there is an advantage that a plurality of sliders having the same shape can be produced uniformly as compared to the conventional machining method.

5A and 5B illustrate a silicon binary optical microlens manufactured by using the method of manufacturing a multi-stage structure of the present invention, FIG. 5A is a cross-sectional view of a silicon binary optical microlens in an etched state, and FIG. 5B is a manufactured silicon binary. Sectional view of an optical micro lens.

Silicon binary optical microlenses are formed by stacking a plurality of stages.

As shown in the figure, a mask is applied to the silicon substrate 41 on which the steps located below are formed to have a wider gap 46A, and a gap 46B on the silicon substrate on which the steps are formed to be narrowed on a silicon substrate. Is applied.

That is, the slit gap 46C of the step 42C located at the top end is formed the narrowest, and the slit gap 46A of the step 42A located at the bottom is formed the widest.

As described above, after the mask is applied in the mask coating step, the silicon binary optical microlens is formed through an etching step, a mask cleaning step, and a barrier rib removing step.

As described above, the present invention forms a silicon binary optical microlens composed of several stages by applying a single mask, thereby reducing the number of processes compared to the conventional method of applying and etching a mask for each stage. In addition to shortening, it is possible to prevent misalignment that may occur by applying a plurality of masks.

6A to 6D illustrate a structure of an aspheric lens-shaped micro lens mold manufactured by the method of manufacturing a multi-stage structure of the present invention. FIG. 6A is a side cross-sectional view of the micro lens mold in an etched state, and FIG. 6B is a partition wall. Figure 6c is a side cross-sectional view of the mold in the removed state, Figure 6c is a side cross-sectional view of the lens material filled in the mold of Figure 6b, Figure 6c is a side cross-sectional view of the completed lens after removing the mold of Figure 6b.

Aspherical microlenses are also formed by stacking a plurality of stages. As shown, the mask 55 is coated on the silicon substrate 51 having the slit 52A positioned below, and the silicon substrate 51 having the slit 52C disposed thereon is formed thereon. The mask 55 is apply | coated so that the space | interval 56C of a slit may narrow.

As described above, after applying the mask in the mask coating step, the micro lens mold 51 is formed through an etching step, a mask cleaning step, and a barrier rib removing step. After the mold 51 is formed, the material constituting the lens 60 is filled, and then the microlens mold 51 is removed to form the aspherical microlens 60.

In addition to the sliders, silicon binary optical microlenses, and microlens molds enumerated above, the multi-step structure fabrication method of the present invention can be variously applied to fabrication of an inclined surface or a structure having a step.

Although the preferred embodiments of the present invention have been described above by way of example, the scope of the present invention is not limited to these specific embodiments, and may be appropriately changed within the scope described in the claims.

According to the present invention as described above it can be expected the following effects.

First, by forming a multi-level structure using a single photomask, the process can be significantly reduced, and the process error can be reduced.

In addition, since a plurality of structures can be produced simultaneously on a single silicon wafer, there is an advantage that a plurality of structures having the same shape can be produced uniformly.

1A to 1D illustrate a method for manufacturing a multi-step structure using anisotropic etching according to an embodiment of the present invention, according to a manufacturing step,

1A is a cross-sectional view of a state where a mask is applied on a substrate

1B is a cross-sectional view of the substrate being etched

1C is a cross-sectional view of an oxide film formed on a substrate surface

Figure 1d is a cross-sectional view of the completed structure after the partition is removed

2 to 4 show the structure of the slide produced by the manufacturing method of the present invention,

2 is a perspective view of a slider

3A is a side view of the slide in an etched state

Figure 3b is a side view of the slide with the partition removed

4 is a perspective view showing that the slide of FIG. 2 is formed on a silicon substrate;

5A and 5B illustrate a silicon binary optical microlens manufactured by using the method of manufacturing a multilevel structure according to the present invention.

Fig. 5A is a cross sectional view of a silicon binary optical micro lens in an etched state;

Figure 5b is a cross-sectional view of the finished silicon binary optical micro lens

6A to 6D illustrate the structure of an aspherical lens-shaped micro lens mold manufactured by the method of manufacturing a multi-stage structure according to the present invention.

Fig. 6A is a side cross-sectional view of the micro lens mold in the etched state.

Fig. 6B is a side cross-sectional view of the mold with the partition removed.

FIG. 6C is a side cross-sectional view with the lens material filled in the mold of FIG. 6B

FIG. 6D is a side cross-sectional view of the completed lens after removing the mold of FIG. 6B

** Description of the symbols for the main parts of the drawings **

11, 21, 41, 51, 61: substrate, silicon substrate

14, 24, 44, 54: bulkhead 15: mask

20: Slider 27: Taper

40: binary optical microlens 50: microlens mold

60: microlens

Claims (10)

A mask application step of masking a plurality of slits having a gap on the silicon substrate; Etching the substrate masked in the mask applying step by an anisotropic plasma etching method; A mask cleaning step of cleaning the mask on the substrate etched in the etching step; A barrier rib removing step of removing barrier ribs between the slits by isotropic etching of the substrate cleaned in the mask cleaning step; Multi-step structure manufacturing method using anisotropic etching, characterized in that configured to include. The method of claim 1, The isotropic etching of the barrier rib removing step is an isotropic plasma etching method, characterized in that for using anisotropic etching method. The method of claim 2, wherein the mask applying step In order to manufacture an air floating slider having a taper and an air bearing surface, On the silicon substrate on which the upwardly inclined taper of the air floating slider is formed, a mask is applied so that the interval between the slits becomes narrower, On the silicon substrate on which the upper end of the air bearing surface is formed, the slit spacing is constant and a mask is applied narrowly. The method of manufacturing a multi-stage structure using anisotropic etching, characterized in that the interval between the slits is uniformly applied to the silicon substrate on which the lower end of the air bearing surface is formed. The method of claim 2, wherein the mask applying step To fabricate a silicon binary optical microlens consisting of multiple stages, On the silicon substrate where the lower stage is formed, apply a mask to widen the slit gap, Method of manufacturing a multi-step structure using anisotropic etching, characterized in that the mask is applied to the narrow gap between the slits on the silicon substrate is formed on the end. The method of claim 2, wherein the mask applying step To form an aspherical lens-shaped micro lens mold composed of a plurality of stages, On the silicon substrate where the lower stage is formed, apply a mask to widen the slit gap, Method of manufacturing a multi-step structure using anisotropic etching, characterized in that the mask is applied to the narrow gap between the slits on the silicon substrate is formed on the end. A mask application step of masking a plurality of slits having a gap on the silicon substrate; Etching the silicon substrate masked in the mask applying step by an anisotropic plasma etching method; A mask cleaning step of cleaning the mask of the silicon substrate etched in the etching step; The silicon substrate cleaned in the mask cleaning step is heated in a heating furnace in an oxygen atmosphere to form a silicon oxide film on the surface of the silicon substrate ( Forming a silicon oxide film; A barrier rib removing step of removing the barrier rib between the slits by etching the silicon substrate on which the silicon oxide layer is formed in the silicon oxide layer etchant in the silicon oxide layer forming step; Multi-step structure manufacturing method using anisotropic etching, characterized in that configured to include. The method of claim 6, wherein the mask applying step In order to manufacture an air floating slider having a taper and an air bearing surface, On the silicon substrate on which the upwardly inclined taper of the air floating slider is formed, a mask is applied so that the interval between the slits becomes narrower, On the silicon substrate on which the upper end of the air bearing surface is formed, the slit spacing is constant and a mask is applied narrowly. The method of manufacturing a multi-stage structure using anisotropic etching, characterized in that the interval between the slits is uniformly applied to the silicon substrate on which the lower end of the air bearing surface is formed. The method of claim 6, wherein the mask applying step To fabricate a silicon binary optical microlens consisting of multiple stages, On the silicon substrate where the lower stage is formed, apply a mask to widen the slit gap, Method for manufacturing a multi-level structure using anisotropic etching, characterized in that the mask is applied to the narrow gap between the slits on the silicon substrate on which the end is formed. The method of claim 6, wherein the mask applying step To form an aspherical lens-shaped micro lens mold composed of a plurality of stages, On the silicon substrate where the lower stage is formed, apply a mask to widen the slit gap, Method of manufacturing a multi-step structure using anisotropic etching, characterized in that the mask is applied to the narrow gap between the slits on the silicon substrate is formed on the end. 10. A multistage structure using anisotropic etching produced by the multistage structure manufacturing method of any one of claims 1 to 9.