TWI656363B - Ultra-violet composite grating and plasma device - Google Patents

Abstract

This disclosure relates to an ultraviolet light composite grating and a plasma device. The ultraviolet light composite grating includes a first grid and a second grid. The first grille is provided with a plurality of first perforations, and the second grille is provided with a plurality of second perforations, and the first perforations and the second perforations are arranged alternately. The first grid is made of an opaque material, and the second grid is made of a filter material. Ultraviolet composite grating can filter out ultraviolet light with a wavelength less than 180nm.

Description

Ultraviolet composite grating and plasma device

This disclosure relates to an ultraviolet composite grating, and in particular, to an ultraviolet composite grating suitable for a plasma device.

The development of semiconductor materials has driven the growth of semiconductor devices. In order to improve the device density and efficiency of semiconductor devices and reduce their costs, the stacking, surface properties, and structural design of each layer of thin film in semiconductor devices are actively researched and developed. In order to form different design structures, the etching process is a commonly used process technology. The etching process includes covering the photoresist layer on the semiconductor device to prevent the etchant from eroding the covered area. After the etching process, in order to deposit and / or form a continuous film, the photoresist layer is further removed by plasma treatment.

According to one aspect of this disclosure, an ultraviolet light composite grating is proposed. The ultraviolet light composite grating includes a first grid and a second grid, wherein the second grid is aligned and parallel to the first grid. The first grille is provided with a plurality of first perforations, and the second grille is provided with a plurality of second perforations. These first perforations are staggered Two perforations. The first grid is made of an opaque material. The second grid is made of a filter material, and the filter material can filter out ultraviolet light with a wavelength less than 180 nm.

According to another aspect of the present disclosure, a plasma device is proposed. The plasma device includes a vacuum cavity, a heating device, an ultraviolet light grating, and a radio frequency coil. A gas inlet is provided at the top of the vacuum cavity. The heating device is configured to heat the semiconductor wafer, and the heating device is disposed at the bottom end of the vacuum cavity. The ultraviolet composite grating is disposed between the gas inlet and the heating device, and the ultraviolet composite grating is parallel to the heating surface of the heating device. The vertical projection area of the ultraviolet composite grating is substantially larger than or equal to the vertical projection area of the semiconductor wafer. The ultraviolet light composite grating includes an upper grid and a lower grid. The lower grid is aligned and parallel to the upper grid. The upper grille is provided with a plurality of first perforations, and the lower grille is provided with a plurality of second perforations, wherein the first perforations are staggered from the second perforations. One of the upper grid and the lower grid is made of an opaque material, and the other is made of a filter material, wherein the filter material can filter out ultraviolet light with a wavelength less than 180 nm. The RF coil is arranged between the gas inlet and the ultraviolet light grating.

100/200/300 / 400‧‧‧UV light composite grating

110/120/210/220/230/310/320/330/410/420 / 430‧‧‧Grill

111/121/211/221/231/311/321/331/411/421 / 431‧‧‧perforated

500‧‧‧ Plasma device

510‧‧‧vacuum cavity

510a / 520a‧‧‧Top

510b / 520b‧‧‧ bottom

511‧‧‧Gas inlet

513‧‧‧Gas inlet tube

513a‧‧‧direction

520‧‧‧ Plasma tank

520c‧‧‧ Plasma area

530‧‧‧Heating device

530a‧‧‧heating surface

540‧‧‧semiconductor wafer

550‧‧‧UV composite grating

551 / 552‧‧‧ Grille

551a / 552a‧‧‧perforation

560‧‧‧RF coil

571‧‧‧photon

571a / 571b / 571c / 573a‧‧‧

573‧‧‧ free radical

A-A’‧‧‧cut line

D ₁₂ / D ₁₃ / D ₂₃ ‧‧‧Distance

W ₁ / W ₂ / W ₃ ‧‧‧ Aperture

A better understanding of the aspects of the present disclosure can be obtained from the following detailed description in conjunction with the accompanying drawings. It should be noted that, according to industry standard practice, features are not drawn to scale. In fact, to make the discussion clearer, the dimensions of the features can be arbitrarily increased or decreased.

[FIG. 1A] A three-dimensional schematic diagram of an ultraviolet composite grating according to some embodiments of the present disclosure.

[FIG. 1B] FIG. 1B is a schematic cross-sectional view of an ultraviolet light composite grating cut along a cutting line A-A 'of FIG. 1A according to some embodiments of the present disclosure.

[Fig. 2A] is a schematic three-dimensional view illustrating an ultraviolet composite grating according to some embodiments of the present disclosure.

[Fig. 2B] It is a schematic cross-sectional view illustrating an ultraviolet light composite grating cut along a cutting line A-A 'of Fig. 2A according to some embodiments of the present disclosure.

[FIG. 3A] It is a three-dimensional schematic view showing an ultraviolet composite grating according to some embodiments of the present disclosure.

[FIG. 3B] A schematic cross-sectional view of an ultraviolet light composite grating cut along a cutting line A-A 'of FIG. 3A according to some embodiments of the present disclosure.

[FIG. 4A] It is a three-dimensional schematic view showing an ultraviolet composite grating according to some embodiments of the present disclosure.

[Fig. 4B] It is a schematic cross-sectional view of an ultraviolet light composite grating cut along the cutting line A-A 'of Fig. 4A according to some embodiments of the present disclosure.

[FIG. 5A] A schematic cross-sectional view of a plasma device according to some embodiments of the present disclosure.

[FIG. 5B] FIG. 5B is a schematic cross-sectional view of the ultraviolet composite grating when the plasma device of FIG. 5A generates a plasma according to some embodiments of the present disclosure.

The following disclosure provides many different embodiments or examples to implement different features of the invention. Specific examples of the components and arrangements described below are used to simplify this disclosure. These are, of course, examples only and are not intended as a limitation. For example, in the description, a first feature is formed above a second feature or Above, it may include embodiments where the first feature and the second feature are formed in direct contact, and may also include embodiments where additional features may be formed between the first feature and the second feature, such that the first feature and the second feature Features may not be in direct contact. In addition, this disclosure may repeat reference numbers and / or text in each example. Such repetitions are for simplicity and clarity and are not in themselves intended to specify the relationship between the embodiments and / or configurations discussed.

In addition, spatial relative terms may be used here to facilitate the description to illustrate the relationship between one element or feature and another (other) element or feature as shown in the figure. In addition to the directions shown in the figures, these relative terms are intended to encompass different orientations of the element in use or operation. The device may be positioned differently (rotated 90 degrees or at other orientations), so the same way can be used to interpret the spatially relative descriptors used here. In addition, the term "made of" may refer to terms such as "comprising" or "consisting of."

In the semiconductor process, the etching process is often used to form the required semiconductor structure and the specific structure of each layer in each thin film, such as: trenches, channels, pads, and / or vias. Wherein, the photoresist layer is covered on the area that does not need to be etched to avoid being eroded by the etching medium. After the etching process is performed, the photoresist layer must be further removed to deposit and / or form a continuous film. Generally, the photoresist layer can be removed by plasma treatment. In the plasma treatment, the plasma formed by gas dissociation has both free radicals and low-wavelength ultraviolet photons (that is, high-energy ultraviolet photons). The free radicals can be used to remove the photoresist layer. When these low-wavelength UV photons directly irradiate the semiconductor wafer to be processed, these high-energy UV photons will destroy the semiconductor Bulk wafers, and more severe silicon defects in semiconductor wafers. Accordingly, these ultraviolet photons in the plasma must be filtered by a grating. However, as semiconductor processes become more complex, process steps such as etching, plasma processing, and / or deposition processes also make semiconductor wafers more prone to silicon defects such as vacancy and / or double vacancy. When the number of silicon defects is too large or the range is too large, the semiconductor wafer is easily damaged.

This disclosure discloses an ultraviolet composite grating and its application. With the disclosed ultraviolet composite grating, vacuum ultra-violet (VUV) can be filtered to prevent high-energy ultraviolet photons from directly irradiating the semiconductor wafer, thereby avoiding more silicon defects. In addition, when other filtered ultraviolet photons are irradiated to the semiconductor wafer, silicon defects in the semiconductor wafer can also be effectively recovered, thereby improving the quality of the semiconductor wafer.

Please refer to FIG. 1A and FIG. 1B at the same time, wherein FIG. 1A is a three-dimensional schematic view of an ultraviolet composite grating according to some embodiments of the present disclosure, and FIG. 1B is a cross-section of FIG. 1A according to some embodiments of the present disclosure. A schematic cross-sectional view of a UV composite grating cut by tangent line AA '. The ultraviolet composite grating 100 includes a first grid 110 and a second grid 120, and the second grid 120 is aligned and parallel to the first grid 110. The first grille 110 is provided with a plurality of first perforations 111, and the second grille 120 is provided with a plurality of second perforations 121. The first perforation 111 is staggered with the second perforation 121 so that light cannot directly pass through the first perforation 111 and the second perforation 121 from one side of the ultraviolet composite grating 100 and cannot be irradiated to the other side of the ultraviolet composite grating 100 . It is important to understand that The "directly through the perforation" mentioned here means that the light can pass straight through the perforation without a transmission mechanism such as reflection or refraction.

The first grid 110 is made of an opaque material. In some embodiments, the opaque material may include, but is not limited to, aluminum, other suitable opaque materials, or any combination of the foregoing. The second grid 120 is made of a filter material, and the filter material can filter out ultraviolet light with a wavelength less than 180 nm. In some embodiments, the filter material can filter out vacuum ultraviolet light. In some embodiments, the filter material may include, but is not limited to, a quartz material, a sapphire material, other suitable filter materials, or any combination thereof. In some specific examples, the quartz material may include, but is not limited to, fused quartz with a trade name of GE Type 214, fused quartz with a trade name of GE Type 219, and other quartz materials that can filter out ultraviolet light with a wavelength less than 180 nm Or any combination of the above materials. According to this, since the first grille 110 is made of an opaque material, the second grille 120 is made of a filter material, and the first and second perforations 111 and 121 are staggered, the ultraviolet light The composite grating 100 can shield ultraviolet light with a wavelength less than 180 nm.

In some embodiments, the distance D ₁₂ between the first grid 110 and the second grid 120 is substantially greater than 0 mm and less than or equal to 4 mm. If the first grid 110 and second grid 120 a distance D of 4 mm is greater than _12, a first grid 110 and the distance D ₁₂ of the second grid 120 is too large, the apparent wavelength of less than 180nm UV Through the first perforation 111 and the second perforation 121, the ultraviolet composite grating 100 is passed, so that the ultraviolet composite grating 100 loses the effect of filtering out light having a wavelength less than 180 nm. If the distance D ₁₂ between the first grid 110 and the second grid 120 is equal to 0 mm, and the ultraviolet composite grating 100 is applied to a plasma device, although the ultraviolet composite grating 100 can still filter out ultraviolet light with a wavelength less than 180 nm Light, but the free radicals in the plasma cannot diffuse through the ultraviolet composite grating 100 through the first perforation 111 and the second perforation 121, and the light cannot be removed by these free radicals. Barrier layer. In some embodiments, the distance D ₁₂ between the first grid 110 and the second grid 120 is substantially greater than 1 mm and less than or equal to 3 mm. In some embodiments, the distance D ₁₂ between the first grid 110 and the second grid 120 is substantially 2 mm.

For example, the apertures W ₁ and W _{2 of the} first and second perforations 111 and 121 are substantially 3 mm to 4 mm, respectively. If the pore diameter W _{1 of the} first perforation 111 and / or the pore diameter W _{2 of the} second perforation 121 is less than 3 mm, the excessively small perforations W ₁ and W ₂ will make it difficult for the aforementioned radicals to pass through the first through diffusion. A through hole 111 and a second through hole 121 reduce the removal efficiency of the photoresist layer by free radicals. It should be noted that, although the perforation density can be increased to increase the number of free radical diffusion through perforations to enhance and maintain its benefits, excessively dense perforations will reduce the mechanical strength of the grille and make the grille more difficult to extract. Cracked and chipped during vacuum. Furthermore, the excessively dense perforations also greatly increase the overlapping probability of the first perforations 111 and the second perforations 121, so that the ultraviolet light easily passes through the first perforations 111 and the second perforations 121 that overlap each other directly through the ultraviolet composite grating 100. . If the aperture W _{1 of the} first perforation 111 and / or the aperture W _{2 of the} second perforation 121 is greater than 4 mm, excessively large apertures W ₁ and W _{2 may} easily allow ultraviolet light to pass directly through the first perforation 111 and the second perforation 121. Therefore, the ultraviolet light composite grating 100 cannot shield ultraviolet light with a wavelength less than 180 nm. Similarly, although the overlap probability of the first perforation 111 and the second perforation 121 can be further reduced by reducing the perforation density, the excessively sparse perforation will reduce the number of free radicals passing through the ultraviolet composite grating 100 through diffusion, and Reduce its effectiveness. In some embodiments, the apertures W ₁ and W _{2 of the} first through-hole 111 and the second through-hole 121 are substantially 3.4 mm to 3.5 mm, respectively.

In some embodiments, the ultraviolet composite grating 100 may include at least a third grid. The at least one third grid is aligned and parallel to the first grid 110 and the second grid 120. The third grid is provided with a plurality of third perforations, and the third perforations are staggered from the first perforations 111 of the first grid 110 or the second perforations 121 of the second grid. In other words, the third perforation may be aligned with the first perforation 111 but staggered from the second perforation 121, or the third perforation may be aligned with the second perforation 121 but staggered from the first perforation 111. In this embodiment, the third grid may be disposed between the first grid 110 and the second grid 120, or the third grid may be disposed on one side of the ultraviolet composite grating 100 (that is, adjacent to the first grid 110). (One side of one grid 110, or one side adjacent to the second grid 120).

Please refer to FIG. 2A and FIG. 2B at the same time, wherein FIG. 2A is a three-dimensional schematic view of an ultraviolet composite grating according to some embodiments of the present disclosure, and FIG. 2B is a cross-section of FIG. 2A according to some embodiments of the present disclosure. A schematic cross-sectional view of a UV composite grating cut by tangent line AA '. The ultraviolet composite grating 200 includes a first grid 210, a second grid 220, and a third grid 230. The second grid 220 is aligned and parallel to the first grid 210, and the third grid 230 is aligned and parallel to the first grid 210 and the second grid 220. The second grille 220 is disposed between the first grille 210 and the third grille 230. The first grille 210 is provided with a plurality of first perforations 211, the second grille 220 is provided with a plurality of second perforations 221, and the third grille 230 is provided with a plurality of third perforations 231. The first perforation 211 is staggered with the second perforation 221, and the second perforation 221 The third perforation 231 is staggered. The first perforation 211 can be aligned with the third perforation 231. According to this, from one side of the ultraviolet composite grating 200, light cannot be directly irradiated to the other side of the ultraviolet composite grating 200 through the first through hole 211, the second through hole 221, and the third through hole 231. In some embodiments, the first perforation 211 can be staggered from the third perforation 231, so the first perforation 211, the second perforation 221, and the third perforation 231 are staggered with each other.

One of the first grid 210, the second grid 220, and the third grid 230 is made of an opaque material, and the other is made of a filter material, wherein the filter material can be filtered out. Ultraviolet light with a wavelength less than 180nm. In some embodiments, the opaque material may include, but is not limited to, aluminum, other suitable opaque materials, or any combination of the foregoing. In some embodiments, the filter material may include, but is not limited to, a quartz material, a sapphire material, other suitable filter materials, or any combination of the foregoing materials. In some specific examples, the quartz material may include, but is not limited to, fused silica with a trade name of GE Type 214, fused silica with a trade name of GE Type 219, other quartz materials that can filter out ultraviolet light with a wavelength less than 180 nm, or the above materials random combination. Therefore, since one of the first grid 210, the second grid 220, and the third grid 230 is made of an opaque material, and the other is made of a filter material, light cannot pass directly therethrough. The first perforation 211, the second perforation 221, and the third perforation 231 pass through the ultraviolet composite grating 200, so the ultraviolet composite grating 200 can shield ultraviolet light with a wavelength less than 180 nm. In some embodiments, one of the first grid 210, the second grid 220, and the third grid 230 may be made of a filter material (this grid is referred to as a filter grid for short), and the other may be Made of light-transmitting materials (these grills are referred to as opaque grills for short), among which The perforations are aligned with each other, or the perforations of the opaque grids allow light to pass through the opaque grids directly through the perforations. In this embodiment, from one side of the ultraviolet composite grating 200, light can directly pass through the perforation of the opaque grid and pass through the filter grid (but not through the perforation of the filter grid) to the ultraviolet light composite. The other side of the grating 200. For example, as shown in FIG. 2B, when the first grille 210 and the third grille 230 are made of opaque materials, and the second grille 220 is made of a filter material, light can be emitted from the first grille. A perforation 211 passes through the first grille 210 and passes through the body of the second grille 220 (that is, the second grille 220 does not pass through the second perforation 221) to filter out ultraviolet light having a wavelength less than 180 nm. Then, it passes through the third grid 230 through the third perforation 231 so that light with a wavelength greater than or equal to 180 nm can be irradiated to the other side of the ultraviolet composite grating 200.

Please continue to refer to FIG. 2B, the distance D ₁₂ between the first grid 210 and the second grid 220 is substantially greater than 0 mm and less than or equal to 4 mm, and the distance between the second grid 220 and the third grid 230 D _{23 is} substantially greater than 0 mm and less than or equal to 4 mm. If the distance D ₁₂ and the distance D _{23 are} greater than 4 mm, the distance D ₁₂ between the first grid 210 and the second grid 220 and / or the distance D ₂₃ between the second grid 220 and the third grid 230 is too large. The ultraviolet light with a wavelength less than 180 nm easily passes through the ultraviolet composite grating 200 through the first perforation 211, the second perforation 221, and the third perforation 231, thereby causing the ultraviolet composite grating 200 to lose the effect of filtering light with a wavelength less than 180 nm. . If the distance D ₁₂ between the first grid 210 and the second grid 220 is equal to 0 mm, or the distance D ₂₃ between the second grid 220 and the third grid 230 is equal to 0 mm, and the ultraviolet composite grating When 200 is used in a plasma device, although the ultraviolet composite grating 200 can still filter out ultraviolet light with a wavelength less than 180 nm, the free radicals in the plasma cannot be diffused through the first perforation 211, the second perforation 221, and The third perforation 231 diffuses through the ultraviolet composite grating 200, and the photoresist layer cannot be removed by these radicals. In some embodiments, the distance D ₁₂ between the first grid 210 and the second grid 220 is substantially greater than 1 mm and less than or equal to 3 mm. In some embodiments, the distance D ₁₂ between the first grid 210 and the second grid 220 is substantially 2 mm. In some embodiments, the distance D ₂₃ between the second grid 220 and the third grid 230 is substantially greater than 1 mm and less than or equal to 3 mm. In some embodiments, the distance D ₂₃ between the second grid 220 and the third grid 230 is substantially 2 mm.

The apertures W ₁ , W ₂ and W _{3 of the} first through hole 211, the second through hole 221 and the third through hole 231 are substantially 3 mm to 4 mm, respectively. If the pore diameters W ₁ , W ₂ and / or W _{3 are} less than 3 mm, the excessively small perforations W ₁ , W ₂ and / or W _{3 may} make it difficult for the aforementioned radicals to pass through the first perforation 111 by diffusion. , The second perforation 121 and the third perforation 131, thereby reducing the removal efficiency of the photoresist layer by free radicals. Similarly, although the density of perforations can be increased by increasing the perforation density to increase and maintain the benefits, the excessively dense perforations will reduce the mechanical strength of the grille and cause the grille to be evacuated. Crash and fragmentation. Furthermore, the excessively dense perforations also greatly increase the overlapping probability of the first perforations 211, the second perforations 221, and the third perforations 231, so that the ultraviolet light easily passes through the first perforations 211, the second perforations 221, and The third perforation 231 passes through the ultraviolet composite grating 200. If the aforementioned apertures W ₁ , W ₂ and / or W _{3 are} larger than 4 mm, excessively large apertures W ₁ , W ₂ and W _{3 may} easily allow ultraviolet light to pass directly through the first perforation 211, the second perforation 221 and the third The perforation 231 prevents the ultraviolet composite grating 200 from shielding ultraviolet light with a wavelength less than 180 nm. Similarly, although the overlapping probability of the first perforation 211, the second perforation 221, and the third perforation 231 can be further reduced by reducing the perforation density, the excessively sparse perforation will reduce the free radicals through the ultraviolet composite grating through diffusion. 200 quantity while reducing its benefits. In some embodiments, the pore diameter W ₁ , the pore diameter W ₂ and the pore diameter W ₃ are substantially 3.4 mm to 3.5 mm, respectively.

Please refer to FIG. 3A and FIG. 3B at the same time, wherein FIG. 3A is a three-dimensional schematic view of an ultraviolet composite grating according to some embodiments of the present disclosure, and FIG. 3B is a cross-section of FIG. 3A according to some embodiments of the present disclosure. A schematic cross-sectional view of a UV composite grating cut by tangent line AA '. The ultraviolet composite grating 300 includes a first grid 310, a second grid 320, and a third grid 330. The second grid 320 is aligned and parallel to the first grid 310, and the third grid 330 is aligned and parallel to the first grid 310 and the second grid 320. The first grid 310 is disposed between the third grid 330 and the second grid 320. The first grille 310 is provided with a plurality of first perforations 311, the second grille 320 is provided with a plurality of first perforations 321, and the third grille 330 is provided with a plurality of third perforations 331. The third perforation 331 is aligned with the first perforation 311, and the first perforation 311 and the third perforation 331 are staggered from the second perforation 321. According to this, from one side of the ultraviolet composite grating 300, light cannot be directly irradiated to the other side of the ultraviolet composite grating 300 through the third through hole 331, the first through hole 311, and the second through hole 321.

At least one of the first grid 310, the second grid 320, and the third grid 330 is made of a filter material, and the other is made of an opaque material. When the second grid 320 is made of an opaque material, the first grid 310 and the third grid 330 are made of a filter material. When the second When the grid 320 is made of a filter material, at least one of the first grid 310 and the third grid 330 is made of an opaque material. In some embodiments, the opaque material may include, but is not limited to, aluminum, other suitable opaque materials, or any combination of the foregoing. The aforementioned filter material can filter out ultraviolet light with a wavelength less than 180 nm. In some embodiments, the filter material may include, but is not limited to, a quartz material, a sapphire material, other suitable filter materials, or any combination of the foregoing materials. In some specific examples, the quartz material may include, but is not limited to, fused silica with a trade name of GE Type 214, fused silica with a trade name of GE Type 219, other quartz materials that can filter out ultraviolet light with a wavelength less than 180 nm, or the above materials random combination. Accordingly, since at least one of the first grid 310, the second grid 320, and the third grid 330 is made of a filter material, and the other is made of an opaque material, ultraviolet light The composite grating 200 can shield ultraviolet light having a wavelength of less than 180 nm. It should be understood that, in the ultraviolet composite grating 300, the perforations of the grids (ie, opaque grids) made of opaque materials must be aligned with each other, or allow light to pass through these opaque The perforations of the grid pass directly through these opaque grids.

3B, the distance D ₁₃ between the third grid 330 and the first grid 310 is substantially greater than 0 mm and less than or equal to 4 mm, and the distance between the first grid 310 and the second grid 320 The distance D _{12 is} substantially greater than 0 mm and less than or equal to 4 mm. If the distance D ₁₃ and the distance D _{12 are} greater than 4 mm, the distance D ₁₃ between the third grid 330 and the first grid 310 and / or the distance D ₁₂ between the first grid 310 and the second grid 320 is too large. And it is easy for the ultraviolet light with a wavelength less than 180 nm to pass through the ultraviolet composite grating 300 directly through the third perforation 331, the first perforation 311, and the second perforation 321, so that the ultraviolet composite grating 300 loses the ability to filter out light with a wavelength less than 180 nm. efficacy. If the distance D ₁₃ between the third grid 330 and the first grid 310 is equal to 0 mm, or the distance D ₁₂ between the first grid 310 and the second grid 320 is equal to 0 mm, and the ultraviolet composite grating When the 300 is used in a plasma device, although the ultraviolet composite grating 300 can still filter out ultraviolet light with a wavelength less than 180 nm, the free radicals in the plasma cannot be diffused through the third perforation 331, the first perforation 311, and The second perforation 321 diffuses through the ultraviolet composite grating 300, and the photoresist layer cannot be removed by these radicals. In some embodiments, the distance D ₁₃ between the third grid 330 and the first grid 310 is substantially greater than 1 mm and less than or equal to 3 mm. In some embodiments, the distance D ₁₃ between the third grid 330 and the first grid 310 is substantially 2 mm. In some embodiments, the distance D ₁₂ between the first grid 310 and the second grid 320 is substantially greater than 1 mm and less than or equal to 3 mm. In some embodiments, the distance D ₁₂ between the first grid 310 and the second grid 320 is substantially 2 mm.

The apertures W ₃ , W _1, and W _{2 of the} third perforations 331, the first perforations 311, and the second perforations 321 are substantially 3 mm to 4 mm, respectively. If the pore diameters W ₃ , W ₁ and / or W _{2 are} less than 3 mm, an excessively narrow perforation pore diameter W ₃ , W ₁ and / or W _{2 may} make it difficult for the aforementioned free radicals to pass through the third perforation 331 by diffusion. The first through hole 311 and the second through hole 321 reduce the removal efficiency of the photoresist layer. Similarly, although the density of perforations can be increased by increasing the perforation density to increase and maintain the benefits, the excessively dense perforations will reduce the mechanical strength of the grille and cause the grille to be evacuated. Crash and fragmentation. Furthermore, the excessively dense perforations also greatly increase the overlapping probability of the third perforations 331, the first perforations 311, and the second perforations 321, so that the ultraviolet light easily passes through the third perforations 331, the first perforations 311, and The second perforation 321 passes through the ultraviolet composite grating 300. If the aforementioned apertures W ₃ , W ₁ and / or W _{2 are} larger than 4 mm, excessively large apertures W ₃ , W ₁ and W _{2 may} easily allow ultraviolet light to pass directly through the third perforation 331, the first perforation 311 and the second The perforation 321 prevents the ultraviolet composite grating 300 from shielding ultraviolet light with a wavelength less than 180 nm. Similarly, although the overlap probability of the third perforation 331, the first perforation 311, and the second perforation 321 can be further reduced by reducing the perforation density, the overly sparse perforation will reduce the free radicals through the ultraviolet composite grating through diffusion. 300 quantity while reducing its benefits. In some embodiments, the pore diameter W ₃ , the pore diameter W _1, and the pore diameter W ₂ are substantially 3.4 mm to 3.5 mm, respectively.

Please refer to FIG. 4A and FIG. 4B at the same time, wherein FIG. 4A is a three-dimensional schematic view of an ultraviolet composite grating according to some embodiments of the present disclosure, and FIG. 4B is a cross-sectional view of FIG. 4A according to some embodiments of the present disclosure. A schematic cross-sectional view of a UV composite grating cut by tangent line AA '. The ultraviolet composite grating 400 includes a third grid 430, a first grid 410, and a second grid 420. The second grid 420 is aligned and parallel to the first grid 410, and the third grid 430 is aligned with the first grid 410 and the second grid 420, where the first grid 410 is disposed in the second grid Between the grid 420 and the third grid 430. The third grid 430 is provided with a plurality of third perforations 431, the first grid 410 is provided with a plurality of first perforations 411, and the second grid 420 is provided with a plurality of second perforations 421. The third perforation 431 is staggered from the first perforation 411, and the first perforation 411 is staggered from the second perforation 421. However, the third perforation 431 and the second perforation 421 are partially overlapped in a direction perpendicular to the projection direction of the ultraviolet composite grating 400. It should be noted that although the third perforation 431 and the second perforation 421 partially overlap, the light cannot pass through the third perforation. The hole 431, the first through hole 411 and the second through hole 421 pass directly through the ultraviolet composite grating 400.

One of the third grid 430, the first grid 410, and the second grid 420 is made of an opaque material, and the other is made of a filter material. In some embodiments, the opaque material may include, but is not limited to, aluminum, other suitable opaque materials, or any combination of the foregoing. This filter material can filter out ultraviolet light with a wavelength less than 180nm. In some embodiments, the filter material may include, but is not limited to, a quartz material, a sapphire material, other suitable filter materials, or any combination of the foregoing materials. In some specific examples, the quartz material may include, but is not limited to, fused silica with a trade name of GE Type 214, fused silica with a trade name of GE Type 219, other quartz materials that can filter out ultraviolet light with a wavelength less than 180 nm, or the above materials random combination. In the ultraviolet composite grating 400, one of the third grid 430, the first grid 410, and the second grid 420 is made of an opaque material, and the rest is made of the aforementioned filter material. The third perforation 431 is offset from the first perforation 411, and the first perforation 411 is offset from the second perforation 421, so the ultraviolet light composite grating 400 can filter out ultraviolet light with a wavelength less than 180 nm. In some embodiments, one of the first grille 410, the second grille 420, and the third grille 430 may be made of a filter material by the positions of the first perforations 411, the second perforations 421, and the third perforations 431. Made of (abbreviated as a filter grid), and the rest are made of opaque material (abbreviated as an opaque grid), in which light can pass through the perforations of the opaque grid and shine to the filter The body of the grid (that is, the perforation that does not pass through the filter light grid) to filter out ultraviolet light with a wavelength less than 180 nm.

The distance D ₁₃ between the third grid 430 and the first grid 410 is substantially greater than 0 mm and less than or equal to 4 mm, and the distance D ₁₂ between the first grid 410 and the second grid 420 is substantially greater than 0 mm and less than or equal to 4 mm. If the distance D ₁₃ and / or the distance D _{12 is} greater than 4 mm, the ultraviolet light with a wavelength less than 180 nm can easily pass through the ultraviolet composite grating 400 through the third perforation 431, the first perforation 411 and the second perforation 421. If the foregoing distance D ₁₃ and / or distance D ₁₂ is equal to 0 mm, and the ultraviolet composite grating 400 is applied to a plasma device, radicals cannot pass through the third perforation 431, the first perforation 411, and the second perforation 421, indirectly. Diffuse through the ultraviolet light composite grating 400. In some embodiments, the distance D ₁₃ between the third grid 430 and the first grid 410 is substantially greater than 1 mm and less than or equal to 3 mm. In some embodiments, the distance D ₁₃ between the third grid 430 and the first grid 410 is substantially 2 mm. In some embodiments, the distance D ₁₂ between the first grid 410 and the second grid 420 is substantially greater than 1 mm and less than or equal to 3 mm. In some embodiments, the distance D ₁₂ between the first grid 410 and the second grid 420 is substantially 2 mm.

The apertures W ₃ , W _1, and W _{2 of the} third perforations 431, the first perforations 411, and the second perforations 421 are substantially 3 mm to 4 mm, respectively. If the apertures W ₃ , W ₁ and / or W _{2 are} larger than 4 mm, an excessively large perforation aperture W ₃ , W ₁ and / or W _{2 may} easily cause ultraviolet light to pass through the third perforation 431, the first perforation 411 and the second perforation. 421, directly pass through the ultraviolet composite grating 400. Although the defect of excessive perforation can be eliminated by reducing the perforation density, the excessively sparse perforation will reduce the amount of free radical diffusion through the ultraviolet composite grating 400 and reduce its efficiency. If the apertures W ₃ , W ₁ and / or W _{2 are} less than 3 mm, the excessively narrow perforation apertures W ₃ , W ₁ and / or W ₂ make it difficult for the free radicals to diffuse through the ultraviolet composite grating 400 and reduce light exposure. Removal efficiency of the barrier layer. Although the number of perforations can be increased by increasing the density of perforations, excessively dense perforations will reduce the mechanical strength of the grille and cause the grille to collapse and crack during the vacuuming process. In addition, the excessively dense perforations also greatly increase the overlapping probability of the third perforations 431, the first perforations 411, and the second perforations 421, so that the ultraviolet light passes directly through the ultraviolet composite grating 400 through the overlapping areas of the perforations.

Please refer to FIGS. 5A and 5B at the same time, wherein FIG. 5A is a schematic cross-sectional view of a plasma device according to some embodiments of the present disclosure, and FIG. 5B is a schematic view of FIG. 5A according to some embodiments of the present disclosure. A schematic cross-sectional view of an ultraviolet composite grating when a plasma device generates a plasma. The plasma device 500 includes a vacuum cavity 510, a plasma tank 520, a gas input pipe 513, a heating device 530, an ultraviolet composite grating 550, and a radio frequency coil 560. A gas inlet 511 is provided at the top 510a of the vacuum cavity 510, and a heating device 530 is provided at the bottom 510b of the vacuum cavity 510. The heating device 530 is configured to heat the semiconductor wafer 540, and the semiconductor wafer 540 is placed in the heating device. The heating surface 530a of 530. The plasma tank 520 is disposed in the vacuum chamber 510, and the plasma tank 520 is disposed between the gas inlet 511 and the heating device 530 of the vacuum chamber 510. The internal space of the plasma tank 520 is connected to the vacuum chamber 510. The internal space is such that the vacuum degree of the plasma tank 520 is equal to the vacuum degree of the vacuum cavity 510. The gas input pipe 513 passes through the gas inlet 511 of the vacuum chamber 510 and passes through the top end 520a of the plasma tank 520 and extends into it to input gas into the plasma tank 520 along the direction 513a. The ultraviolet composite grating 550 is disposed between the gas inlet 511 and the heating device 530 of the vacuum cavity 510, and the ultraviolet composite grating 550 is disposed at the bottom end 520b of the plasma tank 520 and completely covers the bottom end 520b of the plasma tank 520. . The RF coil 560 is disposed between the gas inlet 511 of the vacuum cavity 510 and the ultraviolet composite grating 550. The RF coil 560 is disposed between the top end 520a and the bottom end 520b of the plasma tank 520 and is wound around the plasma tank 520 outer. Corresponding to the winding position of the RF coil 560, a plasma region 520c is provided inside the plasma groove 520. It can be understood that the plasma region 520c refers to a region where the gas is dissociated into a plasma when the gas is input into the plasma tank 520 through the gas input pipe 513. In some embodiments, the gas may include, but is not limited to, NO, CO, CF, CF ₂ , He, Cl ₂ , CCl, BCl, and other plasmas that can be dissociated to include free radicals and ultraviolet photons (wavelengths less than 300 nm) Gas, or any combination of the above.

The ultraviolet composite grating 550 is parallel to the heating surface 530a of the heating device 530, so the ultraviolet composite grating 550 is parallel to the semiconductor wafer 540. In some embodiments, the vertical projection area of the ultraviolet composite grating 550 is substantially greater than or equal to the vertical projection area of the semiconductor wafer 540. As shown in FIG. 5B, the ultraviolet composite grating 550 includes an upper grid 551 and a lower grid 552, and the upper grid 551 is aligned and parallel to the lower grid 552. The upper grille 551 is provided with a plurality of first perforations 551a, and the lower grille 552 is provided with a plurality of second perforations 552a, wherein the first perforations 551a are staggered from the second perforations 552a so that light cannot pass through the first perforations 551a and the second The perforation 552a passes directly through the ultraviolet composite grating 550. One of the upper grid 551 and the lower grid 552 is made of an opaque material, and the other is made of a filter material, wherein the filter material can filter out ultraviolet light with a wavelength less than 180 nm. In some embodiments, the opaque material may include, but is not limited to, aluminum, other suitable opaque materials, or the foregoing materials. Mix the materials randomly. In some embodiments, the filter material may include, but is not limited to, a quartz material, a sapphire material, other suitable filter materials, or any combination of the foregoing materials. In some specific examples, the quartz material may include, but is not limited to, fused silica with a trade name of GE Type 214, fused silica with a trade name of GE Type 219, other quartz materials that can filter out ultraviolet light with a wavelength less than 180 nm, or the above materials random combination.

In some embodiments, the distance D ₁₂ between the upper grille 551 and the lower grille 552 is substantially greater than 0 mm and less than or equal to 4 mm. In some embodiments, the distance D ₁₂ between the upper grille 551 and the lower grille 552 is substantially greater than 1 mm and less than or equal to 3 mm. In some embodiments, the distance D ₁₂ between the upper grill 551 and the lower grill 552 is substantially 2 mm. In some embodiments, the perforations 551a of the first and second perforated aperture W ₁ W ₂ have an aperture 552a of the substance is 3 mm to 4 mm. In some embodiments, the perforations 551a of the first aperture and the second aperture of the hole W ₁ W ₂ have substantial 552a of 3.4 mm to 3.5 mm.

In some embodiments, the ultraviolet composite grating 550 may include at least one auxiliary grid, and the auxiliary grid may be aligned and parallel to the upper grid 551 and the lower grid 552. Wherein, at least one auxiliary grille is respectively provided with a plurality of third perforations, and the third perforations are staggered from the first perforations and the second perforations. In some embodiments, the auxiliary grille may be disposed between the upper grille 551 and the lower grille 552. In some embodiments, the auxiliary grille may be disposed above the upper grille 551 or below the lower grille 552. In some embodiments, the auxiliary grid may be made of a filter material, and the filter material is the same as the aforementioned filter material.

For example, please continue to refer to FIGS. 5A and 5B. Among them, for the convenience of explanation and understanding, the grid 551 above FIG. 5B is made of an opaque material. 5B is made of a filter material. It can be understood that the materials of the upper grille 551 and the lower grille 552 are only for convenience of explanation, and are not intended to limit the present case. Those with ordinary knowledge in the technical field to which this case belongs can appropriately change the materials of the upper grille 551 and the lower grille 552. When the vacuum degree between the vacuum cavity 510 and the plasma tank 520 reaches the set value, the gas is input into the plasma tank 520 through the gas input pipe 513 and along the direction 513a, and a voltage is applied to the RF coil, and the input gas is A plasma may be formed in the plasma region 520c.

When the gas is dissociated into a plasma, the plasma may include photons 571, radicals 573, and the like. The photon 571 travels straight along the path 571a. Among them, when the photon 571 is irradiated onto the opaque upper grid 551, the photon 571 is reflected by the path 571b due to the reflection characteristics of the opaque material (for example, aluminum). Furthermore, when the photon 571 passes through the first perforation 551a and is irradiated to the lower grid 552, due to the filtering characteristics of the filter material (for example, quartz material), ultraviolet light having a wavelength less than 180 nm is filtered out, and the wavelength is Ultraviolet light greater than or equal to 180 nm continues on path 571c and is irradiated onto semiconductor wafer 540 to process the surface thereof. The aforementioned radical 573 is diffused through the first perforation 551a of the upper grid 551 and the second perforation 552a of the lower grid 552 by a path 573a to pass through the ultraviolet composite grating 550, and the surface of the semiconductor wafer 540 deal with.

In some embodiments, for example, when the gas is a mixed gas of oxygen and nitrogen, the plasma formed by dissociation includes radicals and ultraviolet photons with a wavelength less than 300 nm. Among them, the free radicals can pass through the ultraviolet composite grating by diffusion and remove the photoresist on the surface of the semiconductor wafer. When UV photons pass through the UV composite grating, the wavelength is less than 180 UV light at nm will be filtered out, and UV light with a wavelength greater than or equal to 180 nm can illuminate the semiconductor wafer and restore silicon defects in the semiconductor wafer, such as: vacancy (vancacy) and / or double vacancy (divancacy), And improve the quality of semiconductor wafers. In some embodiments, the aforementioned ratio of oxygen to nitrogen is substantially 10: 1 to 1: 1. In some embodiments, the ratio of oxygen to nitrogen is substantially 10: 1 to 2: 1. If the amount of oxygen used is less than the amount of nitrogen, the removal rate of the photoresist is reduced, and the removal efficiency of the photoresist is reduced. If the aforementioned ratio of oxygen to nitrogen is greater than 10: 1, in the nitrogen oxide plasma dissociated by the mixed gas, the spectral intensity of the ultraviolet photons is weak, and the benefit of the plasma treatment is reduced.

For example, in some embodiments, when a mixed gas of oxygen and nitrogen (wherein the ratio of oxygen to nitrogen is 1: 1) is passed into the plasma tank, the nitrogen oxide plasma formed by dissociation has a wavelength of 200 nm to 300nm UV Photon. Since the photon energy of ultraviolet light with a wavelength of 254nm is about 4.9eV, and this photon energy is equivalent to the bonding energy of silicon atoms, the ultraviolet light with a wavelength of 254nm can induce the silicon atoms of the silicon wafer irradiated by it A bond is formed to recover silicon defects such as vacancies and / or double vacancies.

Those skilled in the art should understand that not all advantages must be discussed here. For all embodiments or examples, no specific advantage is necessary, and other embodiments or examples may provide different advantages.

According to one aspect of this disclosure, an ultraviolet light composite grating is proposed. The ultraviolet light composite grating includes a first grid and a second grid, wherein the second grid is aligned and parallel to the first grid. The first grille is provided with a plurality of first perforations, and the second grille is provided with a plurality of second perforations. These first perforations are staggered Two perforations. The first grid is made of an opaque material. The second grid is made of a filter material, and the filter material can filter out ultraviolet light with a wavelength less than 180 nm.

According to another aspect of the present disclosure, a plasma device is proposed. The plasma device includes a vacuum cavity, a heating device, an ultraviolet light grating, and a radio frequency coil. A gas inlet is provided at the top of the vacuum cavity. The heating device is configured to heat the semiconductor wafer, and the heating device is disposed at the bottom end of the vacuum cavity. The ultraviolet composite grating is disposed between the gas inlet and the heating device, and the ultraviolet composite grating is parallel to the heating surface of the heating device. The vertical projection area of the ultraviolet composite grating is substantially larger than or equal to the vertical projection area of the semiconductor wafer. The ultraviolet light composite grating includes an upper grid and a lower grid. The lower grid is aligned and parallel to the upper grid. The upper grille is provided with a plurality of first perforations, and the lower grille is provided with a plurality of second perforations, wherein the first perforations are staggered from the second perforations. One of the upper grid and the lower grid is made of an opaque material, and the other is made of a filter material, wherein the filter material can filter out ultraviolet light with a wavelength less than 180 nm. The RF coil is arranged between the gas inlet and the ultraviolet light grating.

The features of several embodiments have been outlined above, so those skilled in the art can better understand the aspects of this disclosure. Those skilled in the art should understand that they can easily use this disclosure as a basis to design or retouch other processes and structures to achieve the same purpose and / or achieve the same advantages as the embodiments described herein. Those skilled in the art should also understand that such peer-to-peer architecture does not depart from the spirit and scope of this disclosure, and those skilled in this art can make various changes, substitutions and substitutions without departing from the spirit and scope of this disclosure. modify.

Claims (10)

An ultraviolet light composite grating includes: a first grid provided with a plurality of first perforations, wherein the first grid is made of an opaque material; and a second grid aligned and parallel In the first grille, wherein the second grille is provided with a plurality of second perforations, the second perforations are staggered from the first perforations so that a light cannot pass straight through the first perforations and the plurality of A second perforation, the second grid is made of a filter material that filters out ultraviolet light with a wavelength less than 180 nm, and a distance between the first grid and the second grid is substantially greater than 0 and less than or equal to 4 mm. According to the ultraviolet light composite grating described in item 1 of the scope of patent application, an aperture of each of the first perforations and each of the second perforations is substantially 3 mm to 4 mm, respectively. The ultraviolet composite grating according to item 1 of the patent application scope, wherein the filter material comprises a quartz material. The ultraviolet composite grating according to item 1 of the patent application scope, further comprising: at least a third grid, aligned and parallel to the first grid and the second grid, and the at least one third grid A plurality of third perforations are respectively provided, wherein the third perforations are staggered from the first or second perforations. The ultraviolet light composite grating according to item 4 of the scope of the patent application, wherein each of the at least one third grid is made of a filter material. A plasma device includes: a vacuum chamber, wherein a gas inlet is provided at a top end of one of the vacuum chambers; a heating device is configured to heat a semiconductor wafer, and the heating device is arranged on a bottom of the vacuum chamber An ultraviolet composite grating is disposed between the gas inlet and the heating device and is parallel to a heating surface of the heating device, wherein a vertical projection area of one of the ultraviolet composite gratings is substantially greater than or equal to the semiconductor wafer A vertical projection area, and the ultraviolet composite grating includes: an upper grille provided with a plurality of first perforations; and a lower grille aligned and parallel to the upper grille, and the lower grille is provided with a plurality of Second perforations, wherein the second perforations are staggered from the first perforations, so that a light cannot pass straight through the first perforations and the second perforations, one of the upper grille and the lower grille One is made of an opaque material, and the other of the upper grille and the lower grille is made of a filter material, and the filter material filters out ultraviolet light with a wavelength less than 180 nm, Wherein the upper grille and the lower grille One line from the spirit of greater than 0 and less than or equal to 4 mm; and a radio frequency coil disposed between the gas inlet and the composite grating the UV light. According to the plasma device described in item 6 of the scope of patent application, a hole diameter of each of the first perforations and each of the second perforations is substantially 3 mm to 4 mm, respectively. The plasma device according to item 6 of the patent application scope, wherein the filter material comprises a quartz material. The plasma device according to item 6 of the patent application scope, wherein the ultraviolet light composite grating further comprises: at least one auxiliary grid, aligned and parallel to the upper grid and the lower grid, and the at least one auxiliary grid The grid is respectively provided with a plurality of third perforations, wherein the third perforations are staggered from the first perforations or the second perforations. The plasma device according to item 9 of the scope of the patent application, wherein each of the at least one auxiliary grid is made of a filter material.