Gas flow monitoring method and device and annealing method

Abstract

The invention provides a gas flow monitoring method and device and an annealing method, and the method comprises the steps: providing a monitoring structure, carrying out the annealing process of the monitoring structure in an ammonia atmosphere, and then obtaining the nitrogen-titanium ratio of the annealed monitoring structure, and the ammonia gas flow condition in the ammonia gas atmosphere is obtained according to the nitrogen-titanium proportion in the monitoring structure and the relation model of the nitrogen-titanium proportion and the ammonia gas flow, so that monitoring of the ammonia gas flow is realized, process control is facilitated, and the product quality is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor manufacturing, in particular to a gas flow monitoring method and device and an annealing method. BACKGROUND

[0002] In the manufacturing of radio frequency (RF) devices, the suppression of low flicker noise is one of the core challenges, which directly affects the phase stability and signal-to-noise ratio of high frequency systems. Especially in high-k metal gate (HKMG) structures, the film layer combination of the interface layer and the high-k dielectric layer is prone to produce oxide traps, which makes the low flicker noise worse. One way to improve the low flicker noise is to increase ammonia (NH3) as a process gas when performing an annealing process on the titanium nitride cap layer in the high-k metal gate structure. During the annealing process, the nitrogen (N) ions in the ammonia can be doped into the film layer, reducing the diffusion of oxygen (O) ions, thereby reducing oxide traps and improving low flicker noise. In the prior art, the temperature during the annealing process is usually monitored by an offline monitor, but there are few offline monitors to monitor the process gas. Although increasing the ammonia flow can improve the low flicker noise, it will also cause the reliability-related parameters to decrease, so it is necessary to monitor the ammonia flow. SUMMARY

[0003] The purpose of the present application is to provide a gas flow monitoring method and device and an annealing method to solve the problem of lack of ammonia flow monitoring in the prior art.

[0004] To solve the above technical problems, the present application provides a gas flow monitoring method, which comprises:

[0005] A monitoring structure is provided, which comprises a substrate, an interface layer on the substrate, a high-k dielectric layer on the interface layer, and a titanium nitride layer on the high-k dielectric layer;

[0006] An annealing process is performed on the monitoring structure in an ammonia atmosphere;

[0007] The nitrogen-titanium ratio in the monitoring structure after annealing is obtained; and

[0008] According to the nitrogen-titanium ratio in the monitoring structure and the relationship model between the nitrogen-titanium ratio and the ammonia flow, the ammonia flow in the ammonia atmosphere is obtained.

[0009] Optionally, in the gas flow monitoring method, the relationship model between the nitrogen-titanium ratio and the ammonia flow is obtained by setting the ammonia flow multiple times and obtaining the corresponding nitrogen-titanium ratio.

[0010] Optionally, in the gas flow monitoring method, the relationship model between the nitrogen-titanium ratio and the ammonia flow is a linear function.

[0011] Optionally, in the gas flow monitoring method, the monitoring structure and the radio frequency device to be prepared perform an annealing process in the same ammonia atmosphere.

[0012] Optionally, in the gas flow monitoring method, the ammonia flow condition in the ammonia atmosphere includes appropriate ammonia flow, too large ammonia flow, or too small ammonia flow.

[0013] Optionally, in the gas flow monitoring method, the material of the interface layer includes silicon oxide.

[0014] Optionally, in the gas flow monitoring method, the thickness of the interface layer is between 5 Å and 100 Å, the thickness of the high-K dielectric layer is between 5 Å and 30 Å, and the thickness of the titanium nitride layer is between 5 Å and 30 Å.

[0015] Optionally, in the gas flow monitoring method, the annealing process has a process temperature between 300 °C and 1200 °C, a process time between 1 s and 1000 s, and a process pressure between 5 torr and 780 torr.

[0016] The present application also provides a gas flow monitoring device, which comprises:

[0017] a detection unit configured to obtain a nitrogen-titanium ratio in a monitoring structure; and

[0018] a processing unit configured to obtain an ammonia flow condition according to the nitrogen-titanium ratio in the monitoring structure and a relationship model between the nitrogen-titanium ratio and the ammonia flow.

[0019] The present application also provides an annealing method, which comprises:

[0020] obtaining an ammonia flow condition in an ammonia atmosphere by using the gas flow monitoring method described above; and

[0021] adjusting the input amount of ammonia in the annealing process according to the obtained ammonia flow condition in the ammonia atmosphere.

[0022] In the gas flow monitoring method and device and annealing method provided by the present application, the monitoring structure is provided, annealing process is performed on the monitoring structure in the ammonia atmosphere, the nitrogen-titanium ratio in the annealed monitoring structure is obtained, and the ammonia flow in the ammonia atmosphere is obtained according to the nitrogen-titanium ratio in the monitoring structure and the relationship model of the nitrogen-titanium ratio and the ammonia flow, so as to realize the monitoring of the ammonia flow, facilitate the process control, and improve the product quality. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 FIG. 1 is a flowchart of the gas flow monitoring method according to an embodiment of the present application.

[0024] Figure 2 FIG. 2 is a schematic diagram of the monitoring structure according to an embodiment of the present application.

[0025] Figure 3 FIG. 3 is a schematic diagram of the relationship model of the nitrogen-titanium ratio and the ammonia flow according to an embodiment of the present application.

[0026] Figure 4 FIG. 4 is a structural schematic diagram of the gas flow monitoring device according to an embodiment of the present application.

[0027] In the drawings, the following signs are used:

[0028] 100 - monitoring structure; 110 - substrate; 120 - interface layer; 130 - high-K dielectric layer; 140 - titanium nitride layer.

[0029] 200 - gas flow monitoring device; 210 - detection unit; 220 - processing unit; DETAILED DESCRIPTION

[0030] The gas flow monitoring method and device and annealing method provided by the present application are further described in detail below in combination with the drawings and specific embodiments. According to the following description, the advantages and features of the present application will be more apparent. It should be noted that the drawings are very simplified and use non-precise proportions, and are only used to facilitate and clarify the purpose of assisting the description of the embodiments of the present application.

[0031] The terms used in the present application are merely for the purpose of describing specific embodiments and are not intended to limit the present application. Unless otherwise defined in the present application, technical terms or scientific terms used in the present application should be understood as the common meanings to those skilled in the art. The terms "first", "second" and similar terms used in the description and the claims of the present application do not denote any order, quantity or importance, but are used to distinguish different components. Similarly, the terms "one" or "a" or similar terms do not denote a quantity limitation, but mean that at least one exists. "Multiple" or "several" means two or more. Unless otherwise indicated, the terms "upper", "upper layer", "lower", "lower layer" and the like are merely for the convenience of description and are not limited to a position or a spatial orientation. The terms "include" or "contain" or the like mean that the elements or objects appearing before "include" or "contain" cover the elements or objects listed after "include" or "contain" and their equivalents, and do not exclude other elements or objects. The terms "connected" or "connected" or the like are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The singular forms "a", "said" and "the" used in the specification and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein means and includes any or all possible combinations of one or more associated listed items.

[0032] The core idea of the present application is to provide a gas flow monitoring method to monitor the ammonia flow, facilitate process control and improve product quality. Please refer to Figure 1 , which is a flowchart of the gas flow monitoring method of the embodiment of the present application. As Figure 1 shown, in the embodiment of the present application, the gas flow monitoring method comprises:

[0033] Step S10: providing a monitoring structure, the monitoring structure comprising: a substrate, an interface layer on the substrate, a high-K dielectric layer on the interface layer, and a titanium nitride layer on the high-K dielectric layer;

[0034] Step S20: performing an annealing process on the monitoring structure in an ammonia atmosphere;

[0035] Step S30: obtaining the nitrogen-titanium ratio in the annealed monitoring structure; and

[0036] Step S40: obtaining the ammonia flow condition in the ammonia atmosphere according to the nitrogen-titanium ratio in the monitoring structure and a nitrogen-titanium ratio-ammonia flow relationship model.

[0037] Please refer to Figure 1 andFigure 2 In the embodiments of the present application, a monitoring structure 100 is provided first, which comprises a substrate 110, an interface layer 120 on the substrate 110, a high-K dielectric layer 130 on the interface layer 120, and a titanium nitride layer 140 on the high-K dielectric layer 130.

[0038] The substrate 110 can be a blank substrate, for example, a silicon wafer. In some embodiments of the present application, the interface layer 120 is a silicon oxide layer, which can be formed by a natural oxidation process, a furnace tube process, a deposition process, etc. The thickness of the interface layer 120 is between 5 Å and 100 Å, for example, the thickness of the interface layer 120 can be 5 Å, 10 Å, 20 Å, 50 Å, 70 Å, or 100 Å, etc.

[0039] The high-K dielectric layer 130 can be formed by a deposition process, for example, the high-K dielectric layer 130 can be formed in a CVD (chemical vapor deposition) machine. In some embodiments of the present application, the material of the high-K dielectric layer 130 can be hafnium oxide (HfO2), titanium oxide (TiO2), zirconium oxide (ZrO2), or hafnium titanium oxide (HfTiO x The thickness of the high-K dielectric layer 130 is between 5 Å and 30 Å, for example, the thickness of the high-K dielectric layer 130 can be 5 Å, 10 Å, 15 Å, 20 Å, 25 Å, or 30 Å, etc.

[0040] The titanium nitride layer 140 can be formed by a deposition process, for example, the titanium nitride layer 140 can be formed in a PVD (physical vapor deposition process) machine. The thickness of the titanium nitride layer 140 is between 5 Å and 30 Å, for example, the thickness of the titanium nitride layer 140 can be 5 Å, 10 Å, 15 Å, 20 Å, 25 Å, or 30 Å, etc.

[0041] In some embodiments of the present application, the interface layer 120, the high-K dielectric layer 130, and the titanium nitride layer 140 in the monitoring structure 100 can be formed at the same time as the corresponding film layers in the radio frequency device to be prepared, that is, the formation process and thickness of each film layer can be the same, so that the monitoring of ammonia gas can be better realized to adapt the flow of ammonia gas to the demand in the radio frequency device.

[0042] Then, an annealing process is performed on the monitoring structure 100 in an ammonia atmosphere. The annealing process can be a spike annealing process, a soak annealing process, a laser spike annealing (LSA) process, a flash lamp annealing (DSA) process, a furnace (FUR) process, or the like. In some embodiments of the present application, the annealing process has a process temperature of 300-1200°C, a process time of 1-1000 s, and a process pressure of 5-780 torr. For example, in an embodiment of the present application, the annealing process has a process temperature of 800°C, a process time of 300 s, and a process pressure of 500 torr; in another embodiment of the present application, the annealing process has a process temperature of 1000°C, a process time of 280 s, and a process pressure of 500 torr, and the like.

[0043] In some embodiments of the present application, the monitoring structure 100 and the radio frequency device to be prepared are subjected to the annealing process in the same ammonia atmosphere. For example, the monitoring structure 100 and the radio frequency device to be prepared can be simultaneously placed in the ammonia atmosphere to perform the annealing process, so that the ammonia flow in the preparation of the radio frequency device can be more accurately and more synchronously monitored; for another example, the monitoring structure 100 and the radio frequency device to be prepared can be placed in the ammonia atmosphere to perform the annealing process in adjacent two annealing processes, so that the ammonia flow can be accurately monitored and the process can be easily performed.

[0044] Then, the nitrogen-titanium ratio in the monitoring structure 100 after the annealing is obtained. For example, the monitoring structure 100 can be detected by an XPS (X-ray photoelectron spectrometer) machine to obtain the nitrogen-titanium ratio therein; in some embodiments of the present application, the thickness of each film layer in the monitoring structure 100 can also be obtained, so that more processes can be monitored, for example, the deposition process can be monitored.

[0045] In embodiments of the present application, then, the ammonia flow in the ammonia atmosphere is obtained according to the nitrogen-titanium ratio in the monitoring structure 100 and a relationship model between the nitrogen-titanium ratio and the ammonia flow. The ammonia flow in the ammonia atmosphere can be appropriate, too large, or too small; or can be a specific value.

[0046] In some embodiments of the present application, the relationship model between the nitrogen-titanium ratio and the ammonia flow can be a linear function. For example, Figure 3As shown, for example, in an embodiment of the present application, the relationship model between the nitrogen-titanium ratio and the ammonia flow rate is a linear function: y = 0.0086x + 0.8972, where x represents the ammonia flow rate, y represents the nitrogen-titanium ratio, and the correlation between the two is: R 2 =0.9868. When the nitrogen-titanium ratio in the monitoring structure 100 is measured, the ammonia flow rate in the ammonia atmosphere in the annealing process can be obtained by substituting the linear function. At this time, the specific value of the ammonia flow rate in the ammonia atmosphere in the annealing process is obtained. In some embodiments of the present application, the preset conditions of the annealing process can be further compared, for example, the preset ammonia flow rate of the annealing process is 8 flow / slm, and the ammonia flow rate in the ammonia atmosphere obtained by detection is 7 flow / slm, so that it can be concluded that the ammonia flow rate is too small, and thus the ammonia flow rate input into the annealing process can be increased in time in the next round of annealing process, thereby improving the reliability of the process.

[0047] The relationship model between the nitrogen-titanium ratio and the ammonia flow rate can be obtained by setting the ammonia flow rate multiple times and obtaining the corresponding nitrogen-titanium ratio. For example, in some embodiments of the present application, a plurality of monitoring structure samples can be prepared, and the annealing process can be performed on the monitoring structure samples using a stable annealing machine set initially. Then, the relationship model between the nitrogen-titanium ratio and the ammonia flow rate can be obtained according to the nitrogen-titanium ratio in the annealed monitoring structure sample and the ammonia flow rate set by the stable annealing machine set initially. In other embodiments of the present application, the relationship model between the nitrogen-titanium ratio and the ammonia flow rate can also be obtained by other methods, for example, the relationship model between the nitrogen-titanium ratio and the ammonia flow rate can be obtained by actual sampling combined with simulation.

[0048] In embodiments of the present application, in each annealing process, the ammonia flow rate in the ammonia atmosphere can be quickly and reliably obtained through the monitoring structure 100, so as to realize the monitoring of the ammonia flow rate, facilitate process control, and improve product quality. For an annealing machine that has been used for a long time, its stability will deteriorate, and there will be a large difference between the set ammonia flow rate and the actual ammonia flow rate in the chamber. The gas flow rate monitoring method of the present application can conveniently and timely find such problems, so as to make corresponding corrections and improve the reliability of the process.

[0049] Correspondingly, an embodiment of the present application also provides a gas flow rate monitoring device, please refer to Figure 4 , which is a structural schematic diagram of the gas flow rate monitoring device of the embodiment of the present application. As Figure 4 shown, the gas flow rate monitoring device 200 comprises:

[0050] a detection unit 210, the detection unit 210 is used for obtaining the nitrogen-titanium ratio in the monitoring structure; and,

[0051] a processing unit 220 configured to obtain the ammonia flow condition according to the nitrogen-to-titanium ratio in the monitoring structure and the relationship model between the nitrogen-to-titanium ratio and the ammonia flow.

[0052] In some embodiments of the present application, the detection unit 210 can be an XPS machine, and the processing unit 220 can be a central processing unit or the like loaded with the relationship model between the nitrogen-to-titanium ratio and the ammonia flow. The detection unit 210 provides the nitrogen-to-titanium ratio in the monitoring structure obtained to the processing unit 220, and the processing unit outputs the ammonia flow condition, achieving convenience and reliability of ammonia flow monitoring.

[0053] The embodiments of the present application also provide an annealing method, which comprises:

[0054] obtaining the ammonia flow condition in the ammonia atmosphere by using the gas flow monitoring method as described above; and

[0055] adjusting the input amount of ammonia in the annealing process according to the ammonia flow condition in the ammonia atmosphere obtained.

[0056] In some embodiments of the present application, after obtaining the ammonia flow condition in the ammonia atmosphere by using the gas flow monitoring method as described above, the setting of the annealing machine can be controlled accordingly to perform subsequent annealing processes. For example, if the ammonia flow obtained by the gas flow monitoring method is appropriate, the setting of the annealing machine is maintained to perform subsequent annealing processes; if the ammonia flow obtained is too large, the input amount of ammonia of the annealing machine is reduced to perform subsequent annealing processes; if the ammonia flow obtained is too small, the input amount of ammonia of the annealing machine is increased to perform subsequent annealing processes, thereby improving the reliability of the entire annealing process.

[0057] In the present application, the mention of “one embodiment”, “some embodiments” means that the features, structures or characteristics described in connection with the embodiment are contained in at least one embodiment, at least some embodiments of the present application. Therefore, the appearance of the phrases “in one embodiment”, “in some embodiments” in various places in the present application does not necessarily refer to the same or the same embodiments. In addition, in one or more embodiments, features, structures or characteristics can be combined in any suitable combination and / or sub-combination.

[0058] While certain embodiments of the applications have been described herein in detail as presently preferred, many modifications and variations thereof will be apparent to those skilled in the art. It is therefore to be understood that within the scope of the applications, changes can be made in the generic and specific details of the applications without departing from the spirit or scope thereof. Embodiments of the applications can be combined in any combination, without departing from the spirit and scope of the applications. It will also be understood that various embodiments of the applications can be used alone or in any combination, without departing from the spirit and scope of the applications. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the scope of the appended claims.

Claims

1. A method of monitoring gas flow, characterized by, The gas flow monitoring method comprises: providing a monitoring structure, the monitoring structure comprising: a substrate, an interface layer on the substrate, a high-K dielectric layer on the interface layer, and a titanium nitride layer on the high-K dielectric layer; performing an annealing process on the monitoring structure in an ammonia atmosphere; obtaining a nitrogen-titanium ratio in the monitoring structure after annealing; and obtaining an ammonia flow condition in the ammonia atmosphere according to the nitrogen-titanium ratio in the monitoring structure and a relationship model between the nitrogen-titanium ratio and the ammonia flow.

2. The gas flow monitoring method of claim 1, wherein, The relationship model between the nitrogen-titanium ratio and the ammonia flow is obtained by setting the ammonia flow multiple times and obtaining the corresponding nitrogen-titanium ratio.

3. The gas flow monitoring method of claim 2, wherein, The relationship model between the nitrogen-titanium ratio and the ammonia flow is a linear function.

4. The gas flow monitoring method of claim 1, wherein, The monitoring structure and the radio frequency device to be prepared are subjected to the annealing process in the same ammonia atmosphere.

5. The gas flow monitoring method according to any one of claims 1 to 4, wherein The ammonia flow condition in the ammonia atmosphere includes appropriate ammonia flow, too large ammonia flow, or too small ammonia flow.

6. The gas flow monitoring method according to any one of claims 1 to 4, wherein The material of the interface layer comprises silicon oxide.

7. The gas flow monitoring method according to any one of claims 1 to 4, wherein The thickness of the interface layer is between 5 Å and 100 Å, the thickness of the high-K dielectric layer is between 5 Å and 30 Å, and the thickness of the titanium nitride layer is between 5 Å and 30 Å.

8. The gas flow monitoring method of any one of claims 1 to 4, wherein, The process temperature of the annealing process is between 300 °C and 1200 °C, the process time is between 1 s and 1000 s, and the process pressure is between 5 torr and 780 torr.

9. A gas flow monitoring device, characterized by The gas flow monitoring device comprises: a detection unit for obtaining a nitrogen-titanium ratio in a monitoring structure; and a processing unit for obtaining an ammonia flow condition according to the nitrogen-titanium ratio in the monitoring structure and a relationship model between the nitrogen-titanium ratio and the ammonia flow.

10. An annealing method characterized by, The annealing method comprises: obtaining an ammonia flow condition in an ammonia atmosphere by using the gas flow monitoring method according to any one of claims 1 to 8; and adjusting the input amount of ammonia in the annealing process according to the obtained ammonia flow condition in the ammonia atmosphere.

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