Sample tray and method of using the same

Abstract

The present invention provides a sample tray and a method for using the same. The tray includes a tray body having a chamber, wherein the chamber is connected to the outside through an air inlet and an exhaust hole, the air outlet end of the air inlet is arranged toward the exhaust hole, and the cross-sectional area of ​​the air inlet near the exhaust hole is larger than the cross-sectional area of ​​the exhaust hole away from the air inlet. When in use, a sample is added to the tray, the tray is placed between a gas-uniform plate and a wafer stage, and the air inlet is connected to the air hole on the wafer stage, and etching or deposition operations can be performed after an inert gas is introduced. Based on the Bernoulli principle, the present invention designs a hollow tray that can form a pressure difference with the outside world. After ventilation, the pressure difference is used to absorb the sample, thereby reducing the use of sample pressing devices and components, and achieving precise temperature control through the flow of inert gas, thereby improving the uniformity and integrity of the etching effect.

Description

Technical Field

[0001] The invention belongs to the technical field of tray manufacturing, and in particular relates to a sample tray and a use method thereof. Background Art

[0002] Inductively coupled plasma (ICP) I nductively- c oupled p lasma, referred to as ICP) etching process or inductively coupled plasma chemical vapor deposition (ICP- c hemical v apor d The deposition process of ICP-CVD (Insulator-Chip-Position) is an essential process in various micro-nano processing devices. Because these ICP-based etching or deposition equipment require precise temperature control, especially etching equipment, the chuck or lower plate is generally controlled by its internal water channel and external chiller. Because the temperature of the sample needs to be more accurately controlled, an inert gas with a very small molecular weight and little effect on the etching or deposition process, such as helium (He), is generally introduced as a heat transfer medium between the sample and the chuck, referred to as back helium. Although universities or research institutes have popularized ICP etchers or ICP-CVD deposition equipment, the sample size they study is an unconventional 8-inch or 12-inch silicon-based wafer. For such low-cost R&D users, the general solution is to use a solid metal or ceramic (aluminum nitride or silicon carbide) material tray, but the absence of back helium contact holes or partially opening back helium inlet holes will lead to uneven temperature distribution, which will eventually lead to non-repeatable processes or large-scale fluctuations in the etching or deposition uniformity of the sample. On the other hand, there are also helium-backed trays on the market, but they require a tablet press. The problem with this type of tray is that it blocks some areas, so the overall uniformity becomes poor. Summary of the invention

[0003] In order to overcome the defects in the prior art that the conventional helium-backed tray must use a tablet pressing device to fix the sample, which easily leads to uneven temperature distribution on the sample and poor etching or deposition uniformity, a sample tray and a method of using the same are provided.

[0004] In order to solve the above technical problems, the present invention provides the following technical solution: a sample tray, comprising a tray body with a chamber, wherein the tray body is provided with an air inlet hole, an exhaust hole and a through hole, the chamber is connected to the outside through the air inlet hole, the exhaust hole and the through hole, the air outlet end of the air inlet hole is arranged in the direction of the exhaust hole, and the through hole is arranged on the sample contact surface of the tray body; the cross-sectional area of ​​the air inlet hole at one end close to the exhaust hole and perpendicular to the axial direction of the air inlet hole is S1, and the cross-sectional area of ​​the exhaust hole at one end away from the air inlet hole and perpendicular to the axial direction of the exhaust hole is S2, wherein S1 is greater than S2, so that the external pressure on the sample is greater than the pressure at the through hole, and the airflow passes through the chamber to produce a Bernoulli effect, so that the sample on the tray body is subjected to external pressure and is thereby pressed.

[0005] Preferably, the tray body includes a first plate and a second plate connected to each other, the first plate and the second plate jointly define the chamber, the air inlet and the exhaust hole are arranged on the second plate, and the through hole is arranged on the first plate, so as to facilitate the flexible use and installation of the tray.

[0006] Preferably, the first plate includes a carrying surface and a first edge, the first edge is arranged around the outer circumference of the carrying surface, the height of the carrying surface is lower than the height of the first edge, and the through hole is arranged on the carrying surface to facilitate the placement of the sample and avoid slipping.

[0007] Preferably, the height of the upper surface of the first edge is h1, and the height of the upper surface of the bearing surface is h2, wherein 0.1 mm ≤ h1 - h2 ≤ 0.3 mm, which meets the bearing requirements of the sample.

[0008] Preferably, a plurality of grooves are provided on the first disk, each of the grooves extending radially outward from the center of the first disk, and the plurality of grooves are evenly spaced apart in the circumferential direction of the first disk, and a through hole is provided in each of the grooves, so as to facilitate contact between a small amount of gas and the sample for precise temperature control.

[0009] Preferably, the second plate includes a bottom surface and a second edge, the second edge is arranged around the periphery of the bottom surface, and the height of the bottom surface is lower than the height of the second edge, so as to form the chamber.

[0010] Preferably, the height of the upper surface of the second edge is h3, and the height of the upper surface of the bottom surface is h4, wherein 0.3mm≤h3-h4≤0.5mm, so as to ensure the required space for gas flow to produce Bernoulli effect.

[0011] Preferably, the air inlet is arranged on the bottom surface, and the air outlet is arranged on the second edge, so that the streamline of the air flow intersects with the first plate, ensuring that a small amount of gas enters the through hole.

[0012] Preferably, the first disk and / or the second disk are made of sintered ceramics, wherein the ceramics are aluminum nitride or silicon carbide to ensure good thermal conductivity.

[0013] As another aspect of the present invention, the present invention provides a method for using a sample tray, which includes the following steps: step 1: placing the sample on the tray body and directly contacting the sample with the sample contact surface of the tray body so that there is no obstruction between the through hole and the sample; step 2: placing the tray body between the gas uniformizing plate and the slide stage, and connecting the air inlet to the air hole on the slide stage; step 3: introducing an inert gas into the chamber through the air inlet, a part of the inert gas contacts the sample through the through hole to cool the sample, and the other part is discharged from the chamber through the exhaust hole, thereby generating a Bernoulli effect to stabilize the sample on the tray body, and etching or deposition operations can be performed.

[0014] Beneficial effects of the present invention:

[0015] The present invention applies the Bernoulli principle to the tray and designs a hollow tray that can form a pressure difference with the outside world. After ventilation, the Bernoulli effect is generated to form a pressure difference. The surface of the sample is subjected to external pressure and is then sucked, eliminating the use of a tablet pressing device or component. A small amount of inert gas is in direct contact with the sample, converting traditional indirect heat conduction into direct heat conduction, achieving precise temperature control, and thus improving the uniformity and integrity of the etching effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the position of the tray of the present invention in an ICP etcher and an ICP-CVD deposition device;

[0017] Figure 2 is an exploded view of the pallet of the present invention;

[0018] Figure 3 is a cross-sectional view of a symmetrical arrangement of air holes in a tray of the present invention;

[0019] Figure 4 is a cross-sectional view of the linear arrangement of the air holes of the tray of the present invention;

[0020] Figure 5 It is a schematic diagram of the through hole arrangement of the tray of the present invention;

[0021] Description of reference numerals:

[0022] 1-first plate, 11-groove, 111-through hole, 12-bearing surface, 13-first edge, 2-second plate, 21-air inlet, 22-exhaust hole, 23-bottom surface, 24-second edge, M-chamber, 3-tray body. DETAILED DESCRIPTION

[0023] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0024] This embodiment provides a sample tray that does not require a pressing device. Specifically, Figures 1 to 5 The tray includes a tray body 3 having a chamber M. The tray body 3 is provided with an air inlet 21, an air outlet 22 and a through hole 111. The chamber M is connected to the outside through the air inlet 21, the air outlet 22 and the through hole 111. The through hole 111 is arranged on the sample contact surface of the tray body 3 to ensure that the sample contacts the gas in the chamber M, providing a basis for the airflow to exert force on the sample. The outlet end of the air inlet 21 is arranged toward the exhaust hole 22, and the cross-sectional area of ​​the end of the air inlet 21 close to the exhaust hole 22 is larger than the cross-sectional area of ​​the end of the exhaust hole 22 away from the air inlet 21. Preferably, the cross-sectional area of ​​the end of the air inlet 21 close to the exhaust hole 22 perpendicular to the axial direction of the air inlet 21 is S1, and the cross-sectional area of ​​the end of the exhaust hole 22 away from the air inlet 21 is S2, wherein S1 is larger than S2, so as to increase the flow rate of the air flow and ensure a higher exhaust air flow rate. The inert gas enters the chamber M through the air inlet 21 and is discharged from the exhaust hole 22. Due to the occurrence of the Bernoulli effect, the sample is subjected to a pressure in the chamber M that is lower than the external pressure, and is then squeezed to be stably placed on the tray. Preferably, the volume of the exhaust hole 22 is larger than that of the air inlet 21, so as to ensure that the exhaust volume is greater than the intake volume under the same air flow state.

[0025] The upper surface of the top wall of the tray body 3 is used as the sample contact surface, and the through hole 111 is arranged on the sample contact surface. For the arrangement of the air inlet hole 21 and the exhaust hole 22, this embodiment provides a method, specifically, the air inlet hole 21 and the exhaust hole 22 are respectively arranged on both sides of the tray body 3, and are distributed opposite to each other to ensure that the streamline of the air flow is parallel to the axis of the tray; preferably, this embodiment provides another arrangement method, specifically, the air inlet hole 21 is arranged on the bottom wall of the tray body 3. At this time, the exhaust hole 22 can be arranged on the side wall of the tray body 3, or at the outer peripheral edge of the sample contact surface of the top wall of the tray body 3, so that the streamline of the intake air flow intersects with the top wall of the tray body 3, and the intake air flow flows out through the through hole 111 and the exhaust hole 22 respectively.

[0026] Furthermore, the tray body 3 includes a first tray 1 and a second tray 2 connected to each other, and the connection between the first tray 1 and the second tray 2 can be integrally formed, or spliced ​​or assembled. A plurality of grooves 11 are provided on the first tray 1 to increase the friction between the tray and the sample, and a through hole 111 is provided on the groove 11 to control the small outflow of helium, while increasing the contact area between the helium and the sample and reducing the speed of the helium when contacting the sample. An air inlet 21 and an air outlet 22 are provided on the second tray 2, and a chamber M is provided between the first tray 1 and the second tray 2. Preferably, the splicing or assembly connection between the first tray 1 and the second tray 2 is more convenient for practical operation and enhances flexibility.

[0027] Further, the first tray 1 has a bearing surface 12 and a first edge 13, and the height of the bearing surface 12 is about 0.1-0.3mm lower than the first edge 13, which can meet the bearing requirements of most samples and unconventional samples, and prevent the sample from falling off the tray after moving horizontally on the tray. The groove 11 and the through hole 111 are opened on the bearing surface 12, and are connected with the chamber M, so that a small amount of inert gas can contact the sample on the tray through the groove 11, so as to achieve accurate and efficient temperature control. Preferably, the cross-sectional shape of the groove 11 is an inverted trapezoid, that is, the bottom surface contacting the sample is wider, and the top surface away from the sample is narrower, which can further reduce the speed of the outflowing inert gas and reduce its impact on the sample; preferably, several grooves 11 can be set, and they are arranged radially outward from the center of the bearing surface 12. If the bearing surface 12 is circular, the direction of the groove 11 is the same as the radial direction of the bearing surface 12. The uniform arrangement is more conducive to the uniform cooling of the sample as a whole and the stability of the sample during the etching stage, and avoids displacement of the sample.

[0028] Furthermore, the second tray 2 has a bottom surface 23 and a second edge 24, and the height of the bottom surface 23 is about 0.3-0.5 mm lower than that of the second edge 24, which provides sufficient space support for the Bernoulli effect of the airflow in the chamber M, and does not excessively increase the volume of the tray, so as to maintain convenience in use. The air inlet 21 is arranged on the bottom surface 23, and the exhaust hole 22 is arranged on the second edge 24. The line connecting the air inlet 21 and the exhaust hole 22 intersects with the extended line of the axis perpendicular to the center of the bottom surface 23, and the air inlet 21 is arranged toward the exhaust hole 22, so that the inert gas flows from the middle of the tray to the peripheral edge, and the speed at the exhaust hole 22 is faster, so that the outer edge of the sample on the tray is subjected to a greater pressure / pressure than the center of the sample, and provides a divergent force for the helium flowing out of the through hole 111, thereby further strengthening the dispersion on the basis of the simple active diffusion of helium, improving the uniform cooling effect on the sample, and ensuring the high precision of etching.

[0029] Preferably, the position of the air inlet 21 is not directly opposite to the position of the through hole 111, and the through hole 111 is closer to the exhaust hole 22 than the air inlet 21, so that a small amount of gas can be ensured to enter the through hole 111. Compared with the indirect heat conduction temperature control through the receiving surface 12, the through hole 111 provides a direct contact heat conduction temperature control method, which is more conducive to efficient and accurate temperature control under the premise of ensuring the Bernoulli adsorption effect. When the bottom surface 23 is circular, a plurality of air inlet holes 21 are provided, and they are arranged in concentric circles with the bottom surface 23, and the line connecting the exhaust hole 22 and the nearest air inlet hole 21 intersects with the extended line of the axis perpendicular to the center of the bottom surface 23. The inner diameter of the exhaust hole 22 is larger than the inner diameter of the groove 11 and the air inlet hole 21 to facilitate rapid exhaust.

[0030] Preferably, along the direction of air flow, the cross-sectional shape of the air inlet 21 is an inclined right trapezoidal structure with a narrow top and a wide bottom, the cross-sectional shape of the exhaust hole 22 is a trapezoid, and the cross-sectional area of ​​the air inlet 21 at one end close to the exhaust hole 22 is larger than the cross-sectional area of ​​the exhaust hole 22 at one end away from the air inlet 21, thereby ensuring that the inert gas flows out of the chamber M quickly.

[0031] Preferably, the air inlet holes 21 and the exhaust holes 22 are arranged in groups, with at least two groups being symmetrical, mirror-like or opposite to each other, and the opening position or direction of the air inlet holes 21 must avoid directly facing the groove 11, that is, maintain a certain angle with the groove 11 or the through hole 111, and tilt toward the exhaust hole 22, so that the center and edge of the tray will form a pressure difference due to the inconsistent helium flow rate, thereby sucking the sample.

[0032] When in use, place the sample tray in the position of the ICP etcher and ICP-CVD deposition, and connect the air inlet 21 to the back helium air inlet on the stage one by one. Now the stage has a focus ring and a groove, and the tray can be placed directly inside. The tray material is preferably ceramic or aluminum alloy, which has a large mass and strong rigidity and will not deform. It is conducive to the rapid outflow of gas when the air outlet is small and the air inlet is large, and its heat conduction effect is retained to ensure stability and effect during use. The back helium is passed into the stage and contacts the tray, forming a pressure difference in the chamber M and then absorbing the sample.

[0033] The sample tray provided by the present invention has a tray thickness of 3 mm, an air inlet 21 which is horizontally inclined at 30 degrees and has a diameter of 1.2 mm, an exhaust hole 22 with a diameter of 0.8 mm, a depth of 0.8 mm for the second tray 2, and a depth of 0.2 mm for the first tray 1. During the test, the inert gas may be argon, helium, xenon, neon, hydrogen, nitrogen, or any combination of the above gases. Compared with the air inlet 21 and the exhaust hole 22 which are respectively arranged on both sides of the sample tray, the air inlet 21 is arranged on the bottom surface 23 and is symmetrically arranged in a group with the exhaust hole 22 to avoid the relatively poor uniformity of the air flow distribution caused by the one-way air intake, thereby avoiding the difference in the pressure distribution on the sample and ensuring the overall uniformity.

[0034] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A sample tray, characterized in that: The tray body (3) comprises a chamber (M), the tray body (3) being provided with an air inlet hole (21), an air outlet hole (22) and a through hole (111), the chamber (M) being connected to the outside through the air inlet hole (21), the air outlet hole (22) and the through hole (111), the air outlet end of the air inlet hole (21) being arranged in the direction of the air outlet hole (22), and the through hole (111) being arranged on the sample contact surface of the tray body (3); The cross-sectional area of ​​the end of the air inlet (21) close to the air outlet (22) perpendicular to the axial direction of the air inlet (21) is S1, and the cross-sectional area of ​​the end of the air outlet (22) away from the air inlet (21) perpendicular to the axial direction of the air outlet (22) is S2, wherein S1 is greater than S2, so that the external pressure on the sample is greater than the pressure at the through hole (111); The tray body (3) comprises a first plate (1) and a second plate (2) connected to each other, the first plate (1) and the second plate (2) jointly defining the chamber (M), the second plate (2) being provided with the air inlet hole (21) and the air outlet hole (22), and the first plate (1) being provided with the through hole (111); The first disk (1) is provided with a plurality of grooves (11), each of the grooves (11) extending radially outward from the center of the first disk, and the plurality of grooves (11) are evenly spaced apart in the circumferential direction of the first disk (1), and each of the grooves (11) is provided with the through hole (111); The second plate (2) comprises a bottom surface (23) and a second edge (24), wherein the second edge (24) is arranged around the periphery of the bottom surface (23), and the height of the bottom surface (23) is lower than the height of the second edge (24); The air inlet (21) is arranged on the bottom surface (23), and the air outlet (22) is arranged on the second edge (24), so that a streamline of a portion of the air inlet flow intersects with the first plate (1), and another portion of the air inlet flow is discharged through the air outlet (22).

2. The sample tray according to claim 1, characterized in that: The first plate (1) comprises a bearing surface (12) and a first edge (13), the first edge (13) being arranged around the outer periphery of the bearing surface (12), the height of the bearing surface (12) being lower than the height of the first edge (13), and the through hole (111) being arranged on the bearing surface (12).

3. The sample tray according to claim 2, characterized in that: The height of the upper surface of the first edge (13) is h1, and the height of the upper surface of the bearing surface (12) is h2, wherein 0.1 mm ≤ h1-h2 ≤ 0.3 mm.

4. The sample tray according to claim 1, characterized in that: The height of the upper surface of the second edge (24) is h3, and the height of the upper surface of the bottom surface (23) is h4, wherein 0.3 mm ≤ h3-h4 ≤ 0.5 mm.

5. The sample tray according to claim 1, characterized in that: The first disk (1) and / or the second disk (2) are made of sintered ceramic, wherein the ceramic is aluminum nitride or silicon carbide.

6. The method for using the sample tray according to any one of claims 1 to 5, characterized in that: The following steps are included: Step 1: placing a sample on the tray body (3) and directly contacting the sample contact surface of the tray body (3) so that there is no obstruction between the through hole (111) and the sample; Step 2: placing the tray body (3) between the gas distribution plate and the wafer stage, and connecting the air inlet (21) to the air hole on the wafer stage; Step 3: Inert gas is introduced into the chamber (M) through the air inlet (21); a portion of the inert gas contacts the sample through the through hole (111) and cools the sample; the other portion is discharged from the chamber (M) through the exhaust hole (22), generating a Bernoulli effect to stabilize the sample on the tray body (3), and etching or deposition operations can be performed.

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