Method for improving PVD TiN hole filling

Abstract

The invention provides a method for improving PVD (Physical Vapor Deposition) TiN hole filling, which comprises the following steps: after the Ti concentration on a suite is greater than a set threshold value, forming a protective layer for reducing N2 adsorption on the suite; feeding the wafer into a water removal process cavity to remove adsorbed water and volatile matters; feeding the wafer into a sputtering process cavity for physical sputtering to form a TiN film; and feeding the wafer after the TiN film is formed into a cooling cavity for cooling. The stress of the TiN film is improved, and peeling of the TiN film is avoided.

Description

Technical Field

[0001] The invention relates to the field of semiconductor technology, and in particular to a method for improving PVD TiN hole filling. Background Art

[0002] The PVD (physical vapor deposition) TiN hole filling process has an important influence on the characteristics of semiconductors, especially on the contact resistance of devices. With the increase in the complexity of integrated processes, the requirements for the PVD TiN hole filling process are becoming increasingly higher. In the actual hole filling process, after the chamber continuously operates a large number of single Ti conditions, it is easy for the Ti atmosphere in the chamber to be too concentrated during the growth of PVD TiN, and N2 is adsorbed by the Ti on the kit. This will cause the N2 ratio to be low during the PVD TiN film formation process of the film-forming wafer, incomplete target poisoning, and a low N content in the growing PVD TiN film, which increases the stress of the PVD TiN film and causes warping after the thermal process. When tungsten is subsequently grown, it will be filled into the TiN below along the warped TiN film, causing leakage and seriously affecting the performance of the device.

[0003] In order to solve the above problems, a new method for improving PVD TiN hole filling needs to be proposed. Summary of the invention

[0004] In view of the shortcomings of the prior art mentioned above, the object of the present invention is to provide a method for improving PVD TiN hole filling, so as to solve the problem in the prior art that N2 is adsorbed by Ti on the kit, resulting in a low N2 ratio during PVD TiN film forming on the film-forming wafer, incomplete target poisoning, and a low N content in the grown PVD TiN film, which increases the stress of the PVD TiN film and causes warping after the thermal process.

[0005] To achieve the above objectives and other related objectives, the present invention provides a method for improving PVD TiN hole filling, comprising:

[0006] Step 1: after the Ti concentration on the set is greater than a set threshold, a protective layer for reducing N2 adsorption is formed on the set;

[0007] Step 2: Send the wafer into a dehydration process chamber to remove adsorbed water and volatile matter;

[0008] Step 3, sending the wafer into a sputtering process chamber for physical sputtering to form a TiN film;

[0009] Step 4: sending the wafer with the TiN film formed thereon into a cooling chamber for cooling.

[0010] Preferably, in step 1, after the chamber continuously operates under the single Ti condition, before TiN film formation, the Ti concentration on the kit is greater than a set threshold.

[0011] Preferably, the "after the chamber continuously operates under single-Ti conditions" in step 1 means after the chamber continuously operates under single-Ti conditions of more than 1 kwh.

[0012] Preferably, the material of the protective layer in step 1 is TiN.

[0013] Preferably, the temperature of the cavity for forming the protective layer in step 1 is 0 to 250 degrees Celsius.

[0014] Preferably, the power specification for forming the protective layer in step 1 is 16-20KW.

[0015] Preferably, the time for forming the protective layer in step 1 is set to 120s to 200s.

[0016] Preferably, the cavity pressure for forming the protective layer in step 1 is 3-4 mT.

[0017] Preferably, the method for forming the TiN film in step three comprises: forming TiN by poisoning the target material with N2 passing through the kit; and forming the TiN film on the wafer by bombarding the TiN on the target material with ions.

[0018] Preferably, the nitrogen content of the TiN film in step 4 is not lower than a target value, and the TiN film does not warp after the thermal process.

[0019] As described above, the method for improving PVD TiN hole filling of the present invention has the following beneficial effects:

[0020] The stress of the TiN film of the present invention is improved, thereby preventing the TiN film from peeling off. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Shown is a schematic diagram of the process flow of the present invention;

[0022] Figure 2 It is a schematic diagram showing the formation of a Ti layer on the surface of the kit of the present invention;

[0023] Figure 3 It is a schematic diagram showing the formation of a protective layer on the surface of the Ti layer according to the present invention. DETAILED DESCRIPTION

[0024] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0025] See also Figure 1 The present invention provides a method for improving PVD TiN hole filling, comprising:

[0026] Step 1: Please refer to Figure 1 , the kit 101 can be set on the inner wall of the chamber, and the target material 103 is usually located above the wafer 104. After the chamber continuously operates under the single Ti condition, the kit 101 is covered with a Ti layer 102, and the Ti concentration is greater than the set threshold. After the Ti concentration on the kit 101 is greater than the set threshold, a protective layer 105 for reducing the adsorption of N2 is formed on the kit 101, forming a Figure 3 The structure shown;

[0027] In some embodiments, in step 1, after the chamber continuously operates under the single Ti condition, before TiN film formation, the Ti concentration on the kit 101 is greater than a set threshold.

[0028] In some embodiments, in step 1, after the chamber continuously operates under single-Ti conditions is after the chamber continuously operates under single-Ti conditions of more than 1 kwh.

[0029] In some embodiments, the material of the protective layer 105 in step 1 is TiN, and the surface atmosphere of the kit 101 is changed from Ti to TiN, thereby reducing the adsorption of nitrogen. In other embodiments, the protective layer 105 can also be other known materials that reduce the adsorption of nitrogen.

[0030] In some embodiments, the temperature of the chamber for forming the protective layer 105 in step 1 is 0 to 250 degrees Celsius, for example, 0 degrees Celsius, 50 degrees Celsius, 100 degrees Celsius, 150 degrees Celsius, 200 degrees Celsius, or 250 degrees Celsius.

[0031] In some embodiments, the power specification for forming the protective layer 105 in step 1 is 16-20 KW, for example, 16 KW, 17 KW, 18 KW, 19 KW, 20 KW.

[0032] In some embodiments, the time for forming the protective layer 105 in step 1 is set to 120s to 200s, for example, 120s, 140s, 160s, 180s, or 200s.

[0033] In some embodiments, the pressure of the chamber for forming the protection layer 105 in step 1 is 3-4 mT, for example, 3 mT, 3.5 mT, or 4 mT.

[0034] Step 2: Send the wafer 104 into a dehydration process chamber to remove adsorbed water and volatile matter;

[0035] Step 3: Send the wafer 104 into a sputtering process chamber for physical sputtering to form a TiN film;

[0036] In some embodiments, the method of forming the TiN film in step three includes: forming TiN by poisoning the target 103 with N 2 passing through the kit 101 ; and forming a TiN film on the wafer 104 by bombarding the TiN on the target 103 with ions.

[0037] Step 4: Send the wafer after the TiN film is formed into a cooling chamber for cooling. After the N2 compensation process, the stress of the TiN film is improved, and TiN peeling is avoided.

[0038] In some embodiments, the nitrogen content of the TiN film in step 4 is not less than a target value, and the TiN film does not warp after the thermal process.

[0039] It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner. Therefore, the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0040] In summary, the stress of the TiN film of the present invention is improved, and the peeling of the TiN film is avoided. Therefore, the present invention effectively overcomes various shortcomings of the prior art and has high industrial utilization value.

[0041] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for improving PVD TiN hole filling, characterized in that: At least: Step 1: after the Ti concentration on the set is greater than a set threshold, a protective layer for reducing N2 adsorption is formed on the set; Step 2: Send the wafer into a dehydration process chamber to remove adsorbed water and volatile matter; Step 3, sending the wafer into a sputtering process chamber for physical sputtering to form a TiN film; Step 4: sending the wafer with the TiN film formed thereon into a cooling chamber for cooling.

2. The method for improving PVD TiN hole filling according to claim 1, characterized in that: In step 1, it is defined that after the chamber continuously operates under the single Ti condition, before TiN film formation, the Ti concentration on the kit is greater than the set threshold.

3. The method for improving PVD TiN hole filling according to claim 3, characterized in that: The "after the chamber continuously operates under single-Ti conditions" in step 1 means after the chamber continuously operates under single-Ti conditions of more than 1 kwh.

4. The method for improving PVD TiN hole filling according to claim 1, characterized in that: The material of the protective layer in step 1 is TiN.

5. The method for improving PVD TiN hole filling according to claim 4, characterized in that: The temperature of the cavity for forming the protective layer in step 1 is 0 to 250 degrees Celsius.

6. The method for improving PVD TiN hole filling according to claim 4, characterized in that: The power specification for forming the protective layer in step 1 is 16 to 20 KW.

7. The method for improving PVD TiN hole filling according to claim 4, characterized in that: The time for forming the protective layer in step 1 is set to 120s to 200s.

8. The method for improving PVD TiN hole filling according to claim 4, characterized in that: The pressure of the cavity for forming the protective layer in step 1 is 3-4 mT.

9. The method for improving PVD TiN hole filling according to claim 1, characterized in that: The method for forming the TiN film in step three includes: forming TiN by poisoning the target material with N2 passing through the kit; and forming the TiN film on the wafer by bombarding the TiN on the target material with ions.

10. The method for improving PVD TiN hole filling according to claim 9, characterized in that: The nitrogen content of the TiN film in step 4 is not lower than the target value, and the TiN film does not warp after the thermal process.

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