Abstract
An ion trap device is disclosed with a method of manufacturing thereof including a substrate, first and second RF electrode rails, first and second DC electrodes on either upper or lower side of substrate, and a laser penetration passage connected to ion trapping zone from outer side of the first or second side of substrate. The substrate includes ion trapping zone in space defined by first and second sides of substrate separated by a distance with reference to width direction of ion trap device. The first and second RF electrode rails are arranged in parallel longitudinally of ion trap device. The first RF electrode is arranged on upper side of first side, the second DC electrode is arranged on lower side of first side, the first DC electrode is arranged on upper side of second side, and the second RF electrode rail is arranged on lower side of second side.
Claims
1. A method of manufacturing an ion trap device, the method comprising: forming an electrode pattern on the upper and lower surfaces of a semiconductor substrate by depositing a conductive film on the upper and lower surfaces of the semiconductor substrate, the electrode pattern including a first radio frequency (RF) electrode rail, a second RF electrode rail, at least one first direct-current (DC) electrode, and at least one second DC electrode, wherein the first RF electrode rail and the second RF electrode rail are arranged in parallel along a longitudinal direction of the ion trap device; forming a plurality of processing holes penetrating the semiconductor substrate, wherein each of the plurality of processing holes penetrates the semiconductor substrate from the upper surface to the lower surface; forming a through hole penetrating the semiconductor substrate from a side surface of the semiconductor substrate to the other side surface of the semiconductor substrate, the through hole passing through the each of plurality of processing holes in the semiconductor substrate; and forming, by etching an inner surface of the through hole, an ion trapping zone at a predetermined area in the through hole so that a laser penetration passage is formed along the through hole intersecting the plurality of processing holes and the ion trapping zone, wherein the ion trapping zone is located: at a position along the laser penetration passage different from the plurality of processing holes, and in a space defined by a first side and a second side of the semiconductor substrate separated by a predetermined distance with reference to a width direction of the ion trap device, wherein the width direction is a direction that is perpendicular to the longitudinal direction, wherein the laser penetration passage is arranged in a direction, which is not in parallel along the first RF electrode rail and the second RF electrode rail, and wherein the laser penetration passage is configured to guide a laser to pass through the laser penetration passage.
2. The method according to claim 1, further comprising forming a plurality of etch holes penetrating the semiconductor substrate at a predetermined position on the upper and lower surfaces of the semiconductor substrate; and wherein, in the forming of the plurality of processing holes, the plurality of processing holes is formed by etching the plurality of etch holes such that each of the plurality of processing holes penetrates the semiconductor substrate from the upper to the lower surface.
3. The method according to claim 1, wherein, in the forming of the through hole, the through hole is formed by etching inner surfaces of the processing holes using crystal plane characteristics of the semiconductor substrate.
4. The method according to claim 1, wherein, in the forming of the through hole, the through hole is formed by a surface/bulk micromachining (SBM) process in the processing holes.
5. The method according to claim 1, wherein, in the forming of the through hole, the through hole is formed by removing semiconductor substrate by a Silicon wet etch in the processing holes.
6. The method according to claim 5, wherein, in the removing of semiconductor substrate, semiconductor substrate is removed according to a 111 plane of silicon that constitutes the semiconductor substrate.
7. The method according to claim 1, wherein the laser penetration passage is arranged in a direction, which is set at a predetermined angle between the width direction and the longitudinal direction.
8. A method of manufacturing an ion trap device, the method comprising: forming a plurality of processing holes penetrating a semiconductor substrate, wherein each of the plurality of processing holes penetrates the semiconductor substrate from the upper surface to the lower surface; forming a through hole penetrating the semiconductor substrate from a side surface of the semiconductor substrate to the other side surface of the semiconductor substrate, the through hole passing through the each of plurality of processing holes in the semiconductor substrate; and forming, by etching an inner surface of the through hole, an ion trapping zone at a predetermined area in the through hole so that a laser penetration passage is formed along the through hole intersecting the plurality of processing holes and the ion trapping zone; and forming an electrode pattern on the upper and lower surfaces of a semiconductor substrate by depositing a conductive film on the upper and lower surfaces of the semiconductor substrate, the electrode pattern including a first radio frequency (RF) electrode rail, a second RF electrode rail, at least one first direct-current (DC) electrode, and at least one second DC electrode, wherein the first RF electrode rail and the second RF electrode rail are arranged in parallel along a longitudinal direction of the ion trap device, wherein the ion trapping zone is located: at a position along the laser penetration passage different from the plurality of processing holes, and in a space defined by a first side and a second side of the semiconductor substrate separated by a predetermined distance with reference to a width direction of the ion trap device, wherein the width direction is a direction that is perpendicular to the longitudinal direction, wherein the laser penetration passage is arranged in a direction, which is not in parallel along the first RF electrode rail and the second RF electrode rail, and wherein the laser penetration passage is configured to guide a laser to pass through the laser penetration passage.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) FIGS. 1A, 1B and 1C are perspective views of a structure for explaining the principle of the 3D trap.
(2) FIGS. 2A and 2B are exemplary diagrams of a 2D ion trap.
(3) FIGS. 3A and 3B are exemplary diagrams of a 3D ion trap.
(4) FIG. 4 is a perspective view of an ion trap device 400 according to at least one embodiment of the present invention.
(5) FIG. 5 is a cross-sectional view of the ion trap device cut along line A-A′ in FIG. 4 as viewed in a direction X.
(6) FIG. 6 is a flowchart showing a method of manufacturing an ion trap chip, according to a first embodiment of the present invention.
(7) FIG. 7 is a cross-sectional view of the ion trap chip after performing a step of forming and patterning a first insulating layer and a polysilicon layer (Step S610).
(8) FIG. 8 is a cross-sectional view of the ion trap chip after performing a step of forming and patterning a second insulating layer (Step S620).
(9) FIG. 9 is a cross-sectional view of the ion trap chip after performing a step of forming a second conductive film (Step S630).
(10) FIG. 10 is a cross-sectional view of the ion trap chip after performing a step of forming and patterning a mask pattern (Step S640).
(11) FIG. 11 is a cross-sectional view of the ion trap chip after performing a step of forming a laser path etch hole and an etch hole sidewall overcoating (Step S650).
(12) FIG. 12 is a cross-sectional view of the ion trap chip after performing a step of patterning and penetrating an SiO.sub.2 layer (Step S660).
(13) FIG. 13 is a cross-sectional view of the ion trap chip 400 after performing a step of forming a laser penetration passage (Step S670).
(14) FIG. 14 is a flowchart showing a method of manufacturing an ion trap chip according to a second embodiment of the present invention.
(15) FIG. 15 is a cross-sectional view of the ion trap chip after performing a step of forming a laser path etch hole and an etch hole sidewall overcoating (Step S1410).
(16) FIG. 16 is a cross-sectional view of the ion trap chip after performing a step of patterning and penetrating an SiO.sub.2 layer (Step S1420).
(17) FIG. 17 is a cross-sectional view of the ion trap chip after performing a step of forming a laser penetration passage (Step S1430).
(18) FIG. 18 is a cross-sectional view of the ion trap chip after performing a step of forming a polysilicon layer (Step S1440).
(19) FIG. 19 is a cross-sectional view of the ion trap chip after performing a step of forming an internal electrode pattern (Step S1450).
(20) FIG. 20 is a cross-sectional view of the ion trap chip after performing a step of forming an insulating layer (Step S1460).
(21) FIG. 21 is a cross-sectional view of the ion trap chip 400 after performing a step of forming an external electrode pattern (Step S1470).
(22) FIG. 22 is a cross-sectional view of the ion trap chip 400 after performing a step of penetrating an ion trapping zone (Step S1480).
(23) FIG. 23 is a cross-sectional view of the ion trap chip 400 after performing a step of connecting the ion trapping zone and the laser path (Step S1490).
DETAILED DESCRIPTION
(24) Exemplary embodiments of the present invention are described in detail below with reference to the accompanying drawings.
(25) FIG. 4 is a perspective view of an ion trap device 400 according to at least one embodiment of the present invention, and FIG. 5 is a cross-sectional view of the ion trap device cut along line A-A′ in FIG. 4 as viewed in a direction X.
(26) As shown in FIG. 4, the ion trap device 400 according to at least one embodiment of the present invention includes a semiconductor substrate 410, and at least one first DC electrode 420, at least one second DC electrode 430, a first RF electrode rail 440, a second RF electrode rail 450, and at least one side DC electrode 461, 462 formed over the semiconductor substrate 410
(27) The semiconductor substrate 410 includes an ion trapping zone 480 in a space defined by a first side 411 and a second side 412 separated by a predetermined distance in the width direction of the ion trap device 400. The first RF electrode rail 440 is arranged on the upper side of the first side 411, and the at least one second DC electrode 430 is arranged on the lower side of the first side 411. The at least one first DC electrode 420 is arranged on the upper side of the second side 412, and the second RF electrode rail 450 is arranged on the lower side of the second side 412.
(28) The first RF electrode rail 440 and the second RF electrode rail 450 are arranged in parallel in the longitudinal direction of the ion trap device 400.
(29) As shown in FIG. 4, when the at least one first DC electrode 420 includes a plurality of first DC electrodes 420 and the at least one second DC electrode 430 includes a plurality of second DC electrodes 430, the plurality of first DC electrodes 420 and the plurality of second DC electrodes 430 are respectively arranged in parallel in the longitudinal direction of the ion trap device 400.
(30) With respect to the first RF electrode rail 440 and the second RF electrode rail 450, one or more side DC electrodes 461 and 462 are respectively arranged at regular intervals on opposite sides of the ion trapping zone 480.
(31) The semiconductor substrate 410 further includes a laser penetration passage 471, 472 that allows a laser emitted from an outer side 411-1 of the first side 411 of the semiconductor substrate 410 to pass the ion trapping zone 480 to an outer side 412-1 of the second side 412 of the semiconductor substrate 410. When the laser penetration passage 471, 472 is formed in a direction parallel to the width direction of the longitudinal direction of the semiconductor substrate 410, the laser penetration passage 471, 472 is hard to form, and hence the laser penetration passage 471, 472 is arranged in a direction between the width direction and the longitudinal direction of the ion trap device 400. As shown in FIGS. 4 and 5, the laser can be emitted in a direction that forms a plane with the width direction and the longitudinal direction; however, the present invention is not limited thereto.
(32) A plurality of processing holes 490 is formed along an upper side position or a lower side position of the substrate corresponding to a position of the laser penetration passage 471, 472. The processing holes 490 can be formed according to the process of forming the laser penetration passage 471, 472.
(33) The first and second DC electrodes 420 and 430, the first RF electrode rail 440 and the second RF electrode rail 450, and the DC electrode 461, 462 are respectively connected to connection pads (not shown) to be connected to a DC power source, an RF power source, and a GND. This is obvious to one of ordinary skill in the art, and hence a separate connection pad is omitted from drawing in FIGS. 4 and 5 and a description thereof is omitted accordingly.
(34) FIG. 6 is a flowchart showing a method of manufacturing an ion trap chip, according to a first embodiment of the present invention.
(35) As shown in FIG. 6, the method of manufacturing the ion trap chip according to at least one embodiment of the present invention includes a step of forming and patterning the a insulating layer and a polysilicon layer (Step S610), a step of forming and patterning a second insulating layer (Step S620), a step of forming a second conductive film (Step S630), a step of patterning an electrode pattern and a laser path upper side (Step S640), a step of forming a laser path etch hole and an etch hole sidewall overcoating (Step S650), a step of patterning and penetrating an SiO.sub.2 layer (Step S660), and a step of forming a laser penetration passage (Step S670).
(36) FIG. 7 is a cross-sectional view of the ion trap chip after performing a step of forming and patterning the first insulating layer and the polysilicon layer (Step S610), FIG. 8 is a cross-sectional view of the ion trap chip after performing a step of forming and patterning the second insulating layer (Step S620), FIG. 9 is a cross-sectional view of the ion trap chip after performing a step of forming the second conductive film (Step S630), FIG. 10 is a cross-sectional view of the ion trap chip after performing a step of forming and patterning the mask pattern (Step S640), FIG. 11 is a cross-sectional view of the ion trap chip after performing a step of forming the laser path etch hole and the etch hole sidewall overcoating (Step S650), FIG. 12 is a cross-sectional view of the ion trap chip after performing a step of patterning and penetrating the SiO.sub.2 layer (Step S660), and FIG. 13 is a cross-sectional view of the ion trap chip 400 after performing a step of forming the laser penetration passage (Step S670).
(37) As shown in FIG. 7, in the step of forming and patterning the first insulating layer and the first conductive film (Step S610), an SiO.sub.2 layer is formed by wet oxidation as first insulating layers 710 and 720 on the top surface and the bottom surface of the semiconductor substrate 410, respectively, to insulate the semiconductor substrate 410. Thereafter, a polysilicon (Poly-Si) layer to be used as an internal electrode is deposited by the low pressure chemical vapor deposition (LPCVD) method and doped with POCl.sub.3 to form first conductive films 730 and 740. After forming the first conductive films 730 and 740, the first conductive films 730 and 740 are patterned on the top surface and the bottom surface by the plasma dry etching method to form a portion to be used as an internal electrode at the first and second DC electrodes 420 and 430) and the first and second RF electrodes 440 and 450.
(38) As shown in FIG. 8, in the step of forming and patterning the second insulating layer (Step S620), tetraethyl orthosilicate (TEOS) is deposited as second insulating layers 810 and 820 on the top surface and the bottom surface, respectively, by the plasma enhanced chemical vapor deposition (PECVD), and areas corresponding to the ion trapping zone 480 and an electrode pattern are patterned on the second insulating layers 810 and 820 to form a basis for a side electrode portion and an external electrode portion of the DC electrodes 420 and 430 and the RF electrodes 440 and 450.
(39) As shown in FIG. 9, in the step of forming the second conductive film (Step S630), the polysilicon layers are deposited on the top surface and the bottom surface, respectively, by the LPCVD to form the side electrode portion and the external electrode portion of the DC electrodes 420 and 430 and the RF electrodes 440 and 450, and doped with POCl.sub.3 to form second conductive films 910 and 920.
(40) As shown in FIG. 10, in the step of patterning the electrode pattern and the laser path upper side (Step S640), the TEOS layers are deposited on the top surface and the bottom surface, respectively, by the PECVD, and the TEOS corresponding to the ion trapping zone 480 and the TEOS of an area other than the side electrode portion and the external electrode portion of the DC electrodes 420 and 430 and the RF electrodes 440 and 450 is removed using a hard mask by plasma dry etching to form a mask pattern. After forming the mask pattern, the second conductive films 910 and 920 are patterned by plasma dry etching in a form of the external electrode portions of the DC electrodes 420 and 430 and the RF electrodes 440 and 450 along the mask pattern, and the second insulating layers 810 and 920 and the first conductive films 730 and 740 on the top surface and the bottom surface are patterned by the plasm dry etching.
(41) As shown in FIG. 11, in the step of forming the laser path etch hole and the etch hole sidewall overcoating (Step S650), the first conductive films 730 and 740 corresponding to the ion trapping zone 480 are removed by the plasma dry etching, an etch hole 1110 of a predetermined depth is patterned by the plasma dry etching on the top surface and the bottom surface of the semiconductor substrate 410 at regular intervals along the laser path by using the deep reactive ion etching (DRIE) process, and thereafter an SiO.sub.2 layer 1120 is formed by the wet oxidation on the etch hole to protect sidewalls of the etch hole.
(42) As shown in FIG. 12, SiO.sub.2 layer in the step of patterning and penetrating (Step S660), the SiO.sub.2 layer of an area other than the ion trapping zone 480 and the sidewalls of the etch hole is removed by the plasma dry etching, and thereafter the DRIE process is performed on the corresponding area to penetrate through the semiconductor substrate 410.
(43) As shown in FIG. 13, in the step of forming the laser penetration passage (Step 3670), an area of the semiconductor substrate 410 exposed by the patterning is removed according to the 111 plane of the silicon that constitutes the semiconductor substrate 410 by a Si wet etch (SBM process) using the crystal plane characteristics of the semiconductor substrate 410 to form the laser penetration passage to the ion trapping zone 480 in the processing holes 490, the SiO.sub.2 wet etch is performed on the area to the ion trapping zone 480 in the laser penetration passage 471, 472 to remove the SiO.sub.2 layer 1120 of the corresponding area, mask patterns 1010 and 1020 for etching the substrate formed on the top surface and the bottom surface are removed by the TEOS wet etch process, the conductive film for separating the first RF electrode rail 440 from the side DC electrode 461 is removed, and the conductive film for separating the second RF electrode rail 450 from the side DC electrode 462) is removed.
(44) FIG. 14 is a flowchart showing a method of manufacturing an ion trap chip according to a second embodiment of the present invention.
(45) As shown in FIG. 14, the method of manufacturing the ion trap chip according to the second embodiment of the present invention includes a step of forming a laser path etch hole and an etch hole sidewall overcoating (Step S1410), a step of patterning and penetrating an SiO.sub.2 layer (Step S1420), a step of forming a laser penetration passage (Step S1430), a step of forming a polysilicon layer (Step S1440), a step of forming an internal electrode pattern (Step S1450), a step of forming an insulating layer (Step 31460), a step of forming an external electrode pattern (Step S1470), a step of penetrating an ion trapping zone (Step S1480), and a step of connecting the ion trapping zone and the laser penetration passage (Step S1490).
(46) FIG. 15 is a cross-sectional view of the ion trap chip after performing a step of forming the laser path etch hole and the etch hole sidewall overcoating (Step S1410), FIG. 16 is a cross-sectional view of the ion trap chip after performing a step of patterning the SiO.sub.2 layer and the penetrating process (Step S1420), FIG. 17 is a cross-sectional view of the ion trap chip after performing a step of forming the laser penetration passage (Step S1430), FIG. 18 is a cross-sectional view of the ion trap chip after performing a step of forming the polysilicon layer (Step S1440), FIG. 19 is a cross-sectional view of the ion trap chip after performing a step of forming the internal electrode pattern (Step S1450), FIG. 20 is a cross-sectional view of the ion trap chip after performing a step of forming the insulating layer (Step S1460), FIG. 21 is a cross-sectional view of the ion trap chip 400 after performing a step of forming the external electrode pattern (Step S1470), FIG. 22 is a cross-sectional view of the ion trap chip 400 after performing a step of penetrating the ion trapping zone (Step S1480), and FIG. 23 is a cross-sectional view of the ion trap chip 400 after performing a step of connecting the ion trapping zone and the laser path (Step S1490).
(47) As shown in FIG. 15, in the step of forming the laser path etch hole and the etch hole sidewall overcoating (Step S1410), the TEOS is deposited by the PECVD, a patterning is performed on an upper-side area of the semiconductor substrate 410 corresponding to the laser path at regular intervals by the plasm dry etching to form mask patterns 1510 and 1520 for etching the substrate on the top surface and the bottom surface.
(48) Thereafter, after patterning an etch hole 1530 of a predetermined depth is patterned by plasma dry etching at regular intervals on the top surface and the bottom surface of the semiconductor substrate 410 corresponding to the laser path by the DRIE process, an SiO.sub.2 layer 1540 is formed on the etch hole 1530 by the wet oxidation to protect the sidewalls of the etch hole.
(49) As shown in FIG. 16, in the step of patterning and penetrating the SiO.sub.2 layer (Step S1420), the SiO.sub.2 layer of an area other than the sidewalls of the etch hole is etched by the plasma dry etching, and thereafter the semiconductor substrate 410 is penetrated by performing the DRIE process on the corresponding area.
(50) As shown in FIG. 17, in the step of forming the laser penetration passage (Step S1430), the area of the semiconductor substrate 410 that is exposed by patterning by the Si wet etch (SBM process) using the crystal plane characteristics of the semiconductor substrate 410 is removed according to the 111 plane of the silicon that constitutes the semiconductor substrate 410 to form the laser penetration passage 471, 472 reaching the area corresponding to the laser processing holes 490 and the ion trapping zone 480, the SiO.sub.2 wet etch process is performed on the area from the laser penetration passage 471, 472 to the ion trapping zone 480 to remove the SiO.sub.2 layer 1540 of the corresponding area, and the mask patterns 1510 and 1520 for etching the substrate on the top surface and the bottom surface are removed by the TEOS wet etch process.
(51) As shown in FIG. 18, in the step of forming the polysilicon layer (Step S1440), the etch hole is filled with the polysilicon by a polysilicon deposition using the LPCVD on the top surface and the bottom surface of the semiconductor substrate 410, flat polysilicon layers 1810 and 1820 for the electrode processing are formed, and the polysilicon layers 1810 and 1820 are formed on an inner wall 1830 of the laser penetration passage 471, 472.
(52) As shown in FIG. 19, in the step of forming the internal electrode pattern (Step S1450), a metal film is deposited by sputtering on the top surface and the bottom surface of the semiconductor substrate 410 and patterned by the plasma dry etching to form internal electrodes 1910 and 1920. Materials that are usable in a high vacuum environment, such as aluminum and gold, can be used as the material for the metal film; however, the present invention is not limited to this. The metal film can be formed by depositing material such as aluminum by the sputtering or the evaporation; however, the present invention is not limited to this.
(53) As shown in FIG. 20, in the step of forming the insulating layer (Step S1460), the TEOS is deposited as the insulating layer on the top surface and the bottom surface, and the TEOS corresponding to the ion trapping zone 480 is patterned by the plasma dry etching to form first insulating layers 2010 and 2020.
(54) As shown in FIG. 21, in the step of forming the external electrode pattern (Step S1470), metal films 2110 and 2120 and TEOS 2130 and 2140 are deposited by the sputtering to form the external electrode portions of the DC electrodes 420 and 430 and the RF electrodes 440 and 450 on the top surface and the bottom surface, and the area corresponding to the external electrode portions is patterned by the plasma dry etching.
(55) As shown in FIG. 22, in the step of penetrating the ion trapping zone (Step S1480), an anisotropic DRIE process is performed on the corresponding area of the semiconductor substrate 410 where the ion trapping zone 480 is located, to penetrate the semiconductor substrate 410.
(56) As shown in FIG. 23, in the step of connecting the ion trapping zone and the laser penetration passage (Step S1490), an undercut (a portion cut inside the ion trapping zone) is secured for a slot portion 2210 that has been penetrated corresponding to the ion trapping zone 480 in FIG. 22 by the isotropic DRIE process to achieve a sufficient area for the ion trapping zone 480, to form the ion trapping zone 480, and the TEOS layers 2130 and 2140 of the side electrode portions and the external electrode portions of the DC electrodes 420 and 430 and the RF electrodes 440 and 450 are removed by the SiO.sub.2 wet etch process. In the step of forming the ion trapping zone 480, the isotropic DRIE process is performed to secure the undercut of a sufficient size such that the internal electrodes 1910 and 1920 do not contact the area of the semiconductor substrate 410.
(57) Although exemplary embodiments of the present disclosure have been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the idea and scope of the claimed invention. Specific terms used in this disclosure and drawings are used for illustrative purposes and not to be considered as limitations of the present disclosure. Specific terms used in this disclosure and drawings are used for illustrative purposes and not to be considered as limitations of the present disclosure. Therefore, exemplary embodiments of the present disclosure have been described for the sake of brevity and clarity. Accordingly, one of ordinary skill would understand the scope of the claimed invention is not to be limited by the explicitly described above embodiments but by the claims and equivalents thereof.
INDUSTRIAL APPLICABILITY
(58) As described above, the present disclosure is highly useful in solving the problem of the limited size of the ion trap device to reduce an influence of the laser scattering in the conventional 3D ion trap chip design and suppressing the problem caused by the laser scattering in the ion trap.
