TW202328657A - Device and method for preparing sample for detecting metal ions on surface of silicon wafer - Google Patents

Abstract

The embodiment of the invention discloses a preparation device and method for a silicon wafer surface metal ion detection sample. The preparation device comprises a transparent sealed box body; the plurality of liquid accommodating units are arranged in the sealed box body and comprise to-be-detected liquid tanks and constant-volume liquid tanks; the bearing table is arranged in the sealed box body and is used for bearing a container; the quantitative solution extraction unit is arranged in the sealed box body, and is used for extracting a set volume of liquid from the plurality of liquid accommodating units into the container; the heating unit is arranged in the sealed box body and is positioned below the bearing table; and the heating unit is used for heating a container containing liquid to be detected so as to evaporate and remove the liquid in the container.

Description

Preparation device and method for detecting samples of metal ions on wafer surface

The invention belongs to the technical field of wafer detection, in particular to a preparation device and method for detecting samples of metal ions on the surface of a wafer.

Since the birth of solid-state electronic components, the importance of cleaning the surface of wafer substrates has been recognized in the manufacturing process of semiconductor microelectronic components. The performance, stability and yield of silicon components are greatly affected by metal impurities on the wafer surface. Due to the extreme sensitivity of the semiconductor surface and the sub-micron size characteristics of the components, the requirements for effective cleaning of the original wafer are getting higher and higher. To be precise with the requirements of current wafers, the total metal contamination should be less than 10 ¹⁰ /cm ² , and particles with a size greater than 0.1 μm should be less than 0.1 per square centimeter, that is, on an 8-inch wafer, the number of particles is required Less than 30.

At present, the detection process of metal impurities on the wafer surface includes: cleaning the wafer surface with SC-1 cleaning solution and SC-2 cleaning solution, so that the metal impurities on the wafer surface are deposited into the cleaning solution, and then the metal impurities containing The impurity cleaning solution was evaporated to dryness, and after constant volume, the metal impurity content was measured with an inductively coupled plasma mass spectrometer. However, the traditional SC-1 cleaning solution and SC-2 cleaning solution are mainly composed of ammonia water and hydrogen peroxide, so ammonia gas will volatilize during the process of evaporating the cleaning solution containing metal impurities to dryness, and the volatilized ammonia gas will serious injury to the physical health of the technician.

In view of this, the present invention expects to provide a preparation device and method for detecting metal ions on the surface of a wafer; it is possible to automatically or semi-automatically constant the volume of the cleaning solution containing metal impurities to obtain a sample for detecting metal ions on the surface of the wafer. Samples, while reducing manual participation, avoid the occurrence of safety problems for technicians.

The technical solution of the present invention is achieved in the following way: First, the present invention provides a preparation device for detecting metal ions on the surface of a wafer. The preparation device includes: a transparent sealed box; A liquid containing unit, including a liquid tank to be tested and a constant volume liquid tank; a bearing platform arranged in the sealed box, which is used to support the container; a quantitative solution extraction unit arranged in the sealed box, the quantitative solution extraction unit is used for Separately extract a set volume of liquid from a plurality of liquid storage units into the container; a heating unit arranged in a sealed box and located under the carrying platform, the heating unit is used to heat the container containing the liquid to be tested to evaporate and remove the liquid in the container of liquid.

In a second aspect, the present invention provides a method for preparing a sample for detecting metal ions on the surface of a wafer. The preparation method can be applied to the preparation device of the first aspect. The preparation method includes: using a quantitative solution extraction unit to draw Set the volume of cleaning liquid containing metal impurities into the container; use the heating unit to heat the liquid in the container to evaporate and remove it; use the quantitative solution extraction unit to draw a set amount of constant volume liquid from the constant volume liquid tank to the container for constant volume Capable to obtain samples for the detection of metal ion content on the wafer surface.

The invention provides a preparation device and method for detecting samples of metal ions on the wafer surface; in order to obtain the metal ion content on the wafer surface, in the invention, the cleaning solution containing metal impurities after the wafer is cleaned is loaded into the sample to be tested. The liquid tank, and seal the sealed box in time, then draw the liquid to be measured in the liquid tank to be measured by the quantitative solution extraction unit into the container, and heat the cleaning liquid in the container to evaporate and remove it through the heating unit. Add a certain amount of constant volume liquid to the residue after evaporation to obtain a sample that can be used to detect the metal ion content on the wafer surface.

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention.

Referring to FIG. 1 , it shows the composition of a preparation device 1 for detecting metal ions on the surface of a wafer provided by an embodiment of the present invention. The preparation device 1 includes: a transparent sealed box 10; A plurality of liquid storage units 20 inside, including the liquid tank 201 to be tested and the constant volume liquid tank 202; the bearing platform 30 arranged in the sealed box body 10, the bearing platform 30 is used to support the container 40; it is arranged in the sealed box body 10 The quantitative solution extraction unit 50 inside, the quantitative solution extraction unit 50 is used to extract the liquid of set volume from a plurality of liquid storage units 20 respectively to the container 40; the heating unit that is arranged in the sealed box 10 and is positioned under the carrying platform 30 60 , the heating unit 60 is used to heat the container 40 containing the liquid to be tested to evaporate and remove the liquid in the container 40 .

Understandably, in order to obtain the metal ion content on the surface of the wafer, in the embodiment of the present invention, the cleaning liquid containing metal impurities after the wafer is cleaned is put into the liquid tank 201 to be tested, and the sealed box 10 is sealed in time , and then draw the liquid to be tested with a set volume in the liquid to be tested tank 201 to the container 40 through the quantitative solution extraction unit 50, and heat the cleaning liquid in the container 40 by the heating unit 60 until it is evaporated and removed. Add a certain amount of constant volume liquid to constant volume to obtain a sample that can be used to detect the metal ion content on the wafer surface.

It can be understood that the SC-1 cleaning solution and the SC-2 cleaning solution used to clean the metal impurities on the wafer surface during the specific implementation process, before cleaning the wafer surface, if the SC-1 cleaning solution and the SC-2 cleaning solution When there are metal impurities in the chemical, the preparation device 1 shown in Figure 1 can also be used to obtain samples for detecting the metal ion content in the SC-1 cleaning solution and the SC-2 cleaning solution, thereby obtaining the SC-1 cleaning solution and the SC-2 cleaning solution. 2 The content of metal impurities in the cleaning solution. Therefore, it can be obtained that the accurate content of metal ions on the wafer surface is the metal ion content obtained from the above-mentioned sample for detecting the metal ion content on the wafer surface minus the metal impurity content in the SC-1 cleaning solution and the SC-2 cleaning solution.

In addition, it can be understood that the sealing box 10 in the embodiment of the present invention can prevent the human body damage caused by the volatilization of ammonia gas when the liquid in the container 40 is evaporated and removed, and the transparent sealing box 10 can facilitate technicians to observe the technical operations performed.

For the preparation device 1 shown in Figure 1, in some possible implementations, the constant volume liquid stored in the constant volume liquid tank 202 is a nitric acid solution with a mass concentration of 1% to 10%; optionally, the constant volume liquid is 5 % mass concentration of nitric acid solution.

It should be noted that the set volume of the constant volume liquid extracted by the quantitative solution extraction unit 50 each time is 5ml~20ml.

For the preparation device 1 shown in FIG. 1, in some possible implementations, as shown in FIG. Washing liquid tank 203B; wherein, the first washing liquid tank 203A is used to hold hydrofluoric acid (HF) solution, and the second washing liquid tank 203B is used to hold ultrapure water. It can be understood that when the sample used for the detection of the metal ion content on the surface of the wafer is obtained at a constant volume, after the detection is completed and the sample is removed, the container 40, such as a beaker, needs to be cleaned to facilitate the next preparation work. In the embodiment, the metal impurities remaining in the container 40 can be pickled first with the HF solution in the first cleaning liquid tank 203A, and then the container 40 can be cleaned with ultrapure water in the second cleaning liquid tank 203B to obtain A clean container 40 will not affect the next measurement of the metal impurity content in the liquid to be tested.

For the preparation device 1 shown in FIG. 1 , in some possible implementations, as shown in FIG. 1 , the quantitative solution extraction unit 50 includes: a mechanical arm 501 with three degrees of freedom; The nozzle 502 , the suction nozzle 502 is used to respectively suck a set volume of liquid from the plurality of liquid storage units 20 into the container 40 .

It can be understood that, in the specific implementation process, first, the quantitative solution extraction unit 50 draws a set volume of cleaning solution containing metal impurities from the liquid tank 201 to be tested into the container 40, when the heating unit 60 is used to heat the liquid in the container 40 After evaporation and removal, draw a certain amount of constant volume liquid from the constant volume liquid tank 202 to the container 40 for constant volume by using the suction quantitative solution extraction unit 50. It should be noted that, in order to ensure the accuracy of constant volume, a quantitative The solution extraction unit 50 draws the constant volume liquid in a small amount from the constant volume liquid tank 202 several times; The cleaning liquid tank 203A and the second cleaning liquid tank 203B suck HF solution and ultrapure water in order to clean the container 40 respectively.

It should be noted that, in the specific implementation process, the robotic arm 501 and the suction nozzle 502 are arranged inside the sealed box 10 , and in order to control the movement of the robotic arm 501 , the connected control unit 503 is arranged outside the sealed box 10 .

For the above-mentioned embodiments, in some examples, as shown in FIG. 2 , a plurality of carrying platforms 30 may be provided in the preparation device 1 to carry a plurality of containers 40; Unit 60.

It can be understood that a plurality of carrying platforms 30 are set up to accommodate a plurality of containers 40, and multiple groups of samples for detecting the content of metal ions on the surface of the wafer can be simultaneously obtained during the specific implementation process, so as to obtain an accurate measurement of the metal ions on the surface of the wafer. content.

For the preparation device shown in FIG. 1, in some possible implementations, as shown in FIG. 3, the quantitative solution extraction unit 50 includes: a plurality of liquid pipelines 31 communicated with each liquid storage unit 20, and a plurality of liquid pipelines 31 Pipelines 31 are used to draw a set volume of liquid from multiple liquid storage units 20 into containers 40; a switch unit 32 is provided on each liquid pipeline 31, and the switch unit 32 is used to control the corresponding liquid pipeline 31 connected or closed.

It can be understood that, in the specific implementation process, as shown in FIG. 3 , the liquid pipeline 31 communicated with the liquid tank 201 to be tested is first opened so that a set volume of cleaning liquid containing metal impurities flows into the container 40. When the heating unit 60 is used to After the liquid in the container 40 is evaporated and removed, the liquid pipeline 31 communicated with the constant volume liquid tank 202 is opened again so that a certain amount of constant volume liquid flows into the container 40 for constant volume; After the sample is detected and removed, the liquid pipelines 31 respectively connected to the first washing liquid tank 203A and the second washing liquid tank 203B are opened sequentially to allow the HF solution and ultrapure water to clean the container 40 in sequence.

It should be noted that, in a specific implementation process, each switch unit 32 is connected with a switch control unit (not shown in the figure), so as to connect or close the liquid pipeline 31 in time.

For the preparation device 1 shown in FIG. 2 , in some possible implementations, the heating unit 60 is connected to a power controller 70, and the power controller 70 is used to control the heating unit 60 to heat the liquid in the container 40 with a set power. .

It should be noted that, for the setting of the power controller 70, as shown in FIG. 2 or FIG. When the heating unit 60 or a plurality of heating units 60 are used, a power controller 70 is used for heating control.

Of course, in the specific implementation process, when the preparation device 1 includes a plurality of heating units 60, each heating unit 60 can also be connected with a power controller 70, so that when the container 40 placed in front is equipped with cleaning The liquid can be removed by heating and evaporating first, and the subsequent container 40 can be removed by heating and evaporating sequentially, thereby saving time and improving detection efficiency.

For the preparation device 1 shown in FIG. 1 , in some possible implementations, as shown in FIG. 1 , the preparation device 1 further includes a ventilation pipeline 80 disposed at the top of the sealed box 10 . It can be understood that the cleaning liquid used to clean the metal ions on the surface of the wafer contains ammonia water, which will cause damage to technicians after the ammonia water evaporates into ammonia gas. The ammonia gas is discharged to avoid injury to the technicians when they remove the obtained samples that can be used for the detection of the metal ion content on the wafer surface.

Referring to FIG. 4 , it shows a method for preparing a sample for detecting metal ions on the surface of a wafer provided by an embodiment of the present invention. The preparation method can be applied to the preparation device 1 of the aforementioned technical solution. The preparation method specifically includes:

S401, draw a set volume of cleaning solution containing metal impurities from the liquid tank 201 to be tested through the quantitative solution extraction unit 50 into the container 40;

S402, using the heating unit 60 to heat the liquid in the container 40 until it is evaporated and removed;

S403 , using the quantitative solution extraction unit 50 to draw a set amount of constant volume liquid from the constant volume liquid tank 202 into the container 40 for constant volume to obtain a sample for detecting the metal ion content on the wafer surface.

For the technical solution shown in FIG. 4 , in some examples, the preparation method further includes: after obtaining the sample for detecting the metal ion content on the surface of the wafer, using the quantitative solution extraction unit 50 to extract the liquid from the first cleaning liquid tank 203A and the second The HF solution and the ultrapure water are sequentially sucked into the cleaning liquid tank 203B to clean the container 40 .

It should be noted that: the technical solutions described in the embodiments of the present invention can be combined arbitrarily if there is no conflict.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone familiar with the technical field with ordinary knowledge can easily think of changes or substitutions within the technical scope disclosed in the present invention. All should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the patent application.

1: Preparation device 10: sealed box 20: Liquid containment unit 201: liquid tank to be tested 202: constant volume liquid tank 203A: first washing liquid tank 203B: Second washing liquid tank 30: carrying platform 31: Liquid pipeline 32: switch unit 40: container 50: Quantitative solution extraction unit 501: Mechanical arm 502: Nozzle 503: control unit 60: Heating unit 70: Power controller 80: ventilation pipe S401~S403: Step process

1 is a schematic diagram of the composition of a preparation device for detecting metal ions on the surface of a wafer provided by an embodiment of the present invention; 2 is a schematic composition diagram of a preparation device for detecting metal ions on the surface of a wafer according to another embodiment of the present invention; 3 is a schematic composition diagram of a preparation device for detecting metal ions on the surface of a wafer provided by another embodiment of the present invention; FIG. 4 is a schematic flowchart of a method for preparing a sample for detecting metal ions on a wafer surface provided by an embodiment of the present invention.

1: Preparation device

10: sealed box

20: Liquid containment unit

201: liquid tank to be tested

202: constant volume liquid tank

203A: first washing liquid tank

203B: Second washing liquid tank

30: carrying platform

40: container

50: Quantitative solution extraction unit

501: Mechanical arm

502: Nozzle

503: control unit

60: Heating unit

80: ventilation pipe

Claims (10)

A preparation device for detecting samples of metal ions on a wafer surface, comprising: Transparent sealed box; A plurality of liquid containing units arranged in the sealed box, including a liquid tank to be tested and a constant volume liquid tank; a bearing platform arranged in the sealed box, the bearing platform is used to support the container; A quantitative solution extraction unit arranged in the sealed box, the quantitative solution extraction unit is used to respectively extract a set volume of liquid from a plurality of the liquid storage units into the container; A heating unit arranged in the airtight box and below the carrying platform, the heating unit is used to heat the container containing the liquid to be tested to evaporate and remove the liquid in the container. The device for preparing samples for detecting metal ions on the wafer surface as described in Claim 1, wherein the constant volume liquid stored in the constant volume liquid tank is a nitric acid solution with a mass concentration of 1% to 10%. The preparation device for detecting metal ions on the wafer surface as described in claim 1, wherein the plurality of liquid storage units further include a washing liquid tank, and the washing liquid tank includes a first washing liquid tank and a second washing liquid tank ; Wherein, the first washing liquid tank is used to hold HF solution, and the second washing liquid tank is used to hold ultrapure water. The preparation device for detecting metal ions on the wafer surface as described in claim 1, wherein the quantitative solution extraction unit includes: A robotic arm with three degrees of freedom; The suction nozzle arranged at the front end of the mechanical arm is used for respectively sucking liquid with a set volume from a plurality of the liquid storage units into the container. The preparation device for detecting metal ions on the wafer surface as described in claim 4, wherein the preparation device can be provided with a plurality of the carrying platforms to carry a plurality of the containers; wherein, the bottom of each carrying platform All are equipped with the heating unit. The preparation device for detecting metal ions on the wafer surface as described in claim 1, wherein the quantitative solution extraction unit includes: a plurality of liquid pipelines communicating with each of the liquid storage units, and the liquid pipelines are used to draw a set volume of liquid from a plurality of the liquid storage units into the container; A switch unit arranged on each of the liquid pipelines is used to control the connection or closure of the corresponding liquid pipelines. The preparation device for detecting samples of metal ions on the surface of a wafer as described in any one of claims 1 to 6, wherein the heating unit is connected with a power controller, and the power controller is used to control the heating unit to set the power to The liquid in the container is heated. The preparation device for detecting metal ions on the surface of a wafer as described in Claim 7, wherein the preparation device further includes a ventilation pipeline arranged at the top of the sealed box. A method for preparing a sample for detecting metal ions on the surface of a wafer, mainly applied to the preparation device for detecting samples for detecting metal ions on the surface of a wafer as described in any one of claims 1 to 8, the steps include: Draw a set volume of cleaning solution containing metal impurities from the liquid tank to be tested through the quantitative solution extraction unit into the container; Using the heating unit to heat the liquid in the container until it is evaporated and removed; The quantitative solution extraction unit draws a set amount of constant volume liquid from the constant volume liquid tank into the container for constant volume to obtain a sample for detecting the metal ion content on the wafer surface. The method for preparing a sample for detecting metal ions on the surface of a wafer as described in claim 9, the steps also include: After obtaining the sample for the detection of metal ion content on the wafer surface, use the quantitative solution extraction unit to sequentially suck hydrofluoric acid (HF) solution and ultrapure water from the first cleaning liquid tank and the second cleaning liquid tank to clean the container.