Faceless shower head

Abstract

Substrate processing (e.g., AlO x This invention provides a low-cost showerhead and substrate processing method for system processes. [Solution] The method provides a faceless showerhead in a plasma processing chamber, comprising a body including a backplate but not a faceplate or plenum, a gas supply stem for introducing gas into the showerhead, and a baffle supported adjacent to the backplate or gas supply stem, which is installed in a substrate processing chamber, gas is introduced into the processing chamber through the faceless showerhead, and the substrate is processed.

Description

Technical Field

[0001] <Priority Claim> This application claims the benefit of priority to U.S. Patent Application No. 63 / 089,969, filed Oct. 9, 2020, the entire disclosure of which is hereby incorporated by reference.

[0002] The present disclosure generally relates to showerheads for substrate processing applications, and more particularly, to a faceless showerhead for aluminum oxide (AlO x ) processes.

Background Art

[0003] Conventional showerheads typically include a plenum connected to a plurality of holes in a faceplate to distribute a precursor gas (precursor) into a processing chamber, for example, to achieve uniformity on a desired wafer or feature formation on a substrate. The presence of the plenum and the numerous holes can significantly increase the cost of the showerhead. In one problematic aspect, due to the high film deposition rate in the AlO x process, the hardware for the AlO x process is prone to peeling and particle generation. Other such problems may not be related to the film deposition rate. For example, it is difficult to use conventional dry etching methods such as in-situ cleaning of components such as showerheads. Without in-situ cleaning, the film will accumulate and peel off over time. Addressing this situation will increase inventory, waste, and labor costs in the manufacturing facility because multiple wet cleanings and component replacements are required.

[0004] The background art described herein is for the purpose of generally presenting the content of the present disclosure. The inventions of the presently named inventors are not to be considered as prior art to the present disclosure, either explicitly or implicitly, within the scope described in this background art section and aspects of the description that do not fall within the prior art at the time of filing.

Summary of the Invention

[0005] In some examples, a faceless showerhead comprises a body that includes a backplate but does not include a faceplate or plenum, a gas supply stem for introducing gas into the showerhead, and a baffle supported adjacent to the backplate or gas supply stem.

[0006] In some examples, the faceless showerhead further includes at least one support element for supporting the baffle in a baffle cavity within the backplate or gas supply stem.

[0007] In some cases, the diameter of the backplate ranges from 12mm to 105mm. In other cases, the diameter of the baffle ranges from 2.5mm to 13mm.

[0008] In some cases, the baffle thickness ranges from 0.5 mm to 3 mm. In some cases, the separation distance between the baffle and the backplate ranges from 0.1 mm to 6 mm. In some cases, the separation distance between the baffle and the gas supply stem ranges from 0.5 mm to 6 mm.

[0009] In some examples, the baffle includes an arrangement of one or more through-holes, with the diameter of the through-holes ranging from 0.2 mm to 10 mm. In some examples, the diameter of the inner or outer circular pattern of the through-hole arrangement ranges from 2 mm to 100 mm. In some examples, the diameter of the support element ranges from 1 mm to 10 mm, and the length of the support element ranges from 0.5 mm to 6 mm. [Brief explanation of the drawing]

[0010] Several embodiments are shown in the attached drawings for illustrative purposes only, not for limitation.

[0011] [Figure 1] A schematic diagram of a processing chamber in which several examples of the methods disclosed herein may be used.

[0012] [Figure 2]Aspects of a conventional showerhead according to an embodiment.

[0013] [Figure 3] Exemplary faceless showerhead according to an embodiment.

[0014] [Figure 4A] Aspects of the subject matter of the invention according to an exemplary embodiment. [Figure 4B] Aspects of the subject matter of the invention according to an exemplary embodiment. [Figure 5A] Aspects of the subject matter of the invention according to an exemplary embodiment. [Figure 5B] Aspects of the subject matter of the invention according to an exemplary embodiment. [Figure 6A] Aspects of the subject matter of the invention according to an exemplary embodiment. [Figure 6B] Aspects of the subject matter of the invention according to an exemplary embodiment.

[0015] [Figure 7] Exemplary baffle according to an embodiment.

[0016] [Figure 8] Flowchart including the operations of a method according to some examples.

Mode for Carrying Out the Invention

[0017] The following description includes systems, methods, techniques, instruction sequences, and computer program products that embody exemplary embodiments of the present disclosure. In the following description, for the purpose of explanation, some specific details are set forth in order to provide a thorough understanding of the exemplary embodiments. However, it will be apparent to those skilled in the art that the present disclosure may be practiced without these specific details.

[0018] Part of the disclosure of this patent document may contain content subject to copyright protection. Since this patent document or patent disclosure can be viewed in the patent file or records of the Patent Office, the copyright owner has no objection to its reproduction by anyone, but owns all other copyrights. The following notice applies to all data described below and all data described in the drawings forming part of this application: All copyrights belong to Lam Research Corporation (2020).

[0019] Conventional precursor supply systems use some kind of plenum. The presence of a plenum can result in the above-mentioned disadvantages. Sediments may be trapped in inaccessible plenums or in a large number of small holes. It will be recognized that it is difficult and costly to clean the inside of conventional plenums or holes.

[0020] Therefore, in one aspect, the present disclosure attempts to provide a low-cost version of a showerhead for substrate processing (e.g., AlO x system processes). Some examples of the present disclosure do not require a plenum. Process optimization can be addressed by the configuration of baffles and the type of chemicals, as further explained below. Some examples reduce the cost and maintenance cost of the showerhead. Some embodiments use configurations that significantly reduce the hardware cost while meeting the desired functional specifications in, for example, AlO x processes.

[0021] Referring now to FIG. 1, an exemplary arrangement 100 of a plasma processing chamber is shown. The present subject matter may be used in various semiconductor manufacturing operations and substrate processing operations, but in the example of the figure, the plasma processing chamber is described in terms of plasma enhanced chemical vapor deposition (CVD) or radical enhanced CVD operations, or atomic layer deposition (ALD) operations.

[0022] Those skilled in the art will appreciate that AlO xOther types of ALD processing techniques, such as thermal ALD operation, are known and may incorporate non-plasma processing chambers. An ALD tool is a specialized CVD processing system in which the ALD reaction occurs between two or more chemical species. These two or more chemical species are called precursor gases and are used to form thin film depositions of material on substrates such as silicon wafers used in the semiconductor industry. The precursor gases are then introduced into the ALD processing chamber and react with the substrate surface to form a deposited layer. Generally, the substrate repeatedly interacts with the precursors to deposit one or more layers of material on the substrate, which slowly and gradually increase in thickness. In specific applications, multiple precursor gases may be used to form various types of films in the substrate manufacturing process.

[0023] Figure 1 shows a processing chamber 102 comprising a shower head 104 and a substrate support assembly 108 or pedestal. The shower head 104 may be a shower head electrode. Typically, the substrate support assembly 108 attempts to provide a substantially isothermal surface and may function as both a heating element and a heat sink for the substrate 106. The substrate support assembly 108 may include an electrostatic chuck (ESC) containing a heating element to assist in the processing of the substrate 106 as described above. The substrate 106 may include a wafer containing, for example, an elemental semiconductor material (e.g., silicon (Si) or germanium (Ge)) or a compound semiconductor material (e.g., silicon germanium (SiGe) or gallium arsenide (GaAs)). Other substrates may include dielectric materials such as quartz, sapphire, semicrystalline polymers, or other nonmetallic and non-semiconductor materials.

[0024] During operation, the substrate 106 is loaded into the substrate support assembly 108 through the load port 110. A gas line 114 can supply one or more processing gases (e.g., precursor gases) to the shower head 104. The shower head 104 then supplies one or more processing gases to the plasma processing chamber 102. A gas source 112 (e.g., one or more precursor gas ampoules) for supplying one or more processing gases is coupled to the gas line 114. In some examples, an RF (radio frequency) power supply 116 is coupled to the shower head 104. In other examples, the power supply is coupled to the substrate support assembly 108 or the ESC.

[0025] Before the showerhead 104 and gas line 114 flow downstream, a coupling (not shown) between the point of use (POU) and the manifold controls the inflow of one or more process gases into the plasma processing chamber 102. Typically, and referring to the conventional showerhead 202 shown in Figure 2, the precursor gas may be mixed in or distributed through the plenum 204 of the showerhead 104.

[0026] During operation, the plasma processing chamber 102 is evacuated by a vacuum pump 118. RF power is capacitively coupled between the showerhead 104 and the lower electrode 120, which is contained inside or on top of the substrate support assembly 108. The substrate support assembly 108 is typically supplied with two or more RF frequencies. For example, in various embodiments, the RF frequency may be selected from at least one of approximately 1 MHz, 2 MHz, 13.56 MHz, 27 MHz, 60 MHz, and other desired frequencies. Coils designed to block or partially block specific RF frequencies may be configured as needed. Thus, the specific frequencies described herein are provided simply for ease of understanding. RF power is used to excite one or more processing gases into the plasma in the space between the substrate 106 and the showerhead 104. The plasma can be used to deposit various layers (not shown) on the substrate 106. In other applications, the plasma may be used to etch device features into various layers on the substrate 106. RF power is coupled at least through the substrate support assembly 108. The substrate support assembly 108 may have a built-in heater. The detailed configuration of the processing chamber 102 may vary and may or may not be plasma-based in the use of the showerhead in this example.

[0027] Figure 2 shows a typical arrangement of a conventional showerhead 202 for use in a processing chamber such as the processing chamber 102 described above. The conventional showerhead 202 includes a gas supply stem 206 that communicates with its internal plenum 204. The conventional showerhead 202 includes a backplate 208 and a faceplate 210. The backplate 208 and faceplate 210 may define the walls of the plenum 204. The faceplate 210 includes holes 212 formed inside. The number of holes 212 may be in the thousands. The holes 212 distribute precursors for processing substrates (such as wafers) supported on the substrate support assembly 108 in the processing chamber 102. The conventional showerhead 202 has the above-mentioned drawbacks.

[0028] Figure 3 shows a typical arrangement of an exemplary faceless shower head 302 for use in a processing chamber such as the processing chamber 102 described above. The faceless shower head 302 has no plenum and no faceplate (hence "faceless"). The faceless shower head 302 comprises a back plate 304 and a baffle 306. A gas supply stem 308 supplies precursor gas to the faceless shower head 302. The baffle 306 is connected to the back plate 304 or the gas supply stem 308 by one or more support elements 310. The support elements 310 may function as spacers or separation elements in some examples. In some examples, the baffle 306 functions to suppress and distribute precursor gas coming out of the lower end of the gas supply stem 308. The baffle 306 may or may not have holes formed inside. Other support or separation configurations of the baffle 306 are also possible.

[0029] A term that those skilled in the art may use when describing process optimization in substrate processing or semiconductor technology is "adjusting the knob." This term relates to process elements or chamber parameters that can be fine-tuned to produce a desired process or result (e.g., the formation of specific nano-sized features on a wafer, film thickness, or other substrate properties). Various desired results or outcomes can be obtained or fine-tuned by "adjusting the knob."

[0030] Several examples of the faceless shower head 302 allow for such fine-tuning in various ways. The fine-tuning elements enabled by the faceless shower head 302 may include, for example, the general configuration, position, or dimensions of the faceless shower head 302 itself or of the faceless shower head 302 relative to the substrate 106; the diameter, thickness, or other dimensions of the baffle 306; the arrangement or configuration of the holes in the baffle 306; the diameter or shape of the holes in the baffle 306; the presence or absence of holes in the baffle 306; the separation distance between the baffle 306 and the gas supply stem 308; the separation distance between the baffle 306 and the backplate 304; and the dimensions or arrangement of the support element 310. Other fine-tuning elements are also possible. For example, the baffle may be heated or cooled. The backplate may be heated or cooled. In some examples, the backplate assumes a specific configuration, such as including uneven surfaces. The baffle 306 may be removable or quickly replaceable with a baffle of a different configuration. Next, several specific examples of faceless showerheads will be described.

[0031] The faceless shower head 402 shown in Figures 4A-4B comprises a back plate 404 and a gas supply stem 406. The faceless shower head 402 includes a baffle 408 attached to the lower end of the gas supply stem 406 by one or more support elements 410. As shown in Figure 4A, in this example, three support elements 410 are provided in the form of short rods. In some examples, the support elements 410 are positioned at a specific distance from the center of the baffle 408 and are evenly spaced around its center. The baffle 408 is supported or nested inside a baffle recess or cavity 412 in the back plate 404. Here, the baffle cavity 412 has a conical shape. A wider conical opening will facilitate cleaning of deeper areas. Other baffle cavity shapes are also possible, such as the cylindrical baffle cavity shown in Figure 5A. In the example shown in Figure 4A, the outer or lower surface 418 of the baffle 408 is coplanar with the lower surface 420 of the back plate 404. Other baffle configurations, cavities, and support positions are also possible.

[0032] In Figure 4B, it can be seen that the baffle 408 has one or more through-holes formed to allow gas passage and distribution. In the example shown, there are six through-holes 414, arranged at equal intervals in an outer circular pattern as shown in the figure. The example also includes six through-holes 416 arranged at equal intervals in an inner circular pattern as shown in the figure. Other arrangements are also possible. In some examples, the baffle has no through-holes at all, or at least holes that function as gas passages.

[0033] Figures 5A-5B and 6A-6B show further examples of faceless showerheads 502 and 602. The corresponding components of the faceless showerheads 502 and 602 are referenced in the same way as in Figures 4A-4B. In the exemplary showerhead 602 shown in Figures 6A-6B, the baffle 608 is located in a baffle cavity 622 provided in the stem 606 relative to the backplate 604, for example. In this configuration, the lower surface 618 of the baffle 608 is not coplanar with the lower surface 620 of the backplate 604. Surfaces 618 and 620 can be made coplanar by a suitable long support element 610, if necessary. In the example shown, the cavity 612 is maintained in the backplate 604, but this feature is not necessarily required in other examples. In some embodiments, the lower surface 624 of the stem 606 may be coplanar with the lower surface 620 of the backplate 604.

[0034] The length, arrangement, or configuration of the support elements 410, 510, and 610 can be selected as needed to provide interrelationships or functionality between the components of the faceless showerheads 402, 502, and 602. A given support element 410, 510, and 610 may be removed or quickly replaced with another support element 410, 510, and 610 of a different length or configuration. Referring, for example, to Figure 7, the baffle 708 is supported in the baffle cavity 712 by a support element 710 of a different configuration. In this example, the support element is provided in the form of a lateral support arm, as opposed to an elongated rod. In this case, the baffle 708 is supported by a series of three support arms 710 arranged at equal intervals around the baffle 708, as shown in the figure.

[0035] Referring to the attached diagram, in some examples, the diameter of the backplate is in the range of 12mm to 105mm or 2.5mm to 13mm. In some examples, the diameter of the baffle is in the range of 12mm to 105mm or 2.5mm to 13mm. In the example diagram shown in the drawing (for example, the nested baffle configuration in Figure 5A), the diameter of the baffle is smaller than the diameter of the backplate. In some examples, the thickness of the baffle is in the range of 0.5mm to 3mm. In some examples, the separation distance between the baffle and the backplate is in the range of 0.1mm to 6mm. In some examples, the separation distance between the baffle and the gas supply stem is in the range of 0.5mm to 6mm. In some examples, the diameter of the through-hole is in the range of 0.2mm to 10mm. In some examples, the diameter of the inner or outer circular pattern is in the range of 2mm to 100mm. In some examples, the diameter of the support element is in the range of 1mm to 10mm, and the length of the support element is in the range of 0.5mm to 6mm. Various combinations of fine-tuning elements are possible to achieve the desired process results.

[0036] The baffle and backplate can have shapes other than circular. For example, the baffle or backplate can be one or more different shapes (e.g., triangular, hexagonal, crescent-shaped, or amorphous), or may include them. In some examples, the specific shape of the baffle or backplate allows for further adjustments to a given process.

[0037] In some examples, a hole or column is provided in the center of the baffle or gas supply stem. In some examples, the gas supply stem has a specific inner or outer diameter to allow for further processing. In some examples, the inner diameter of the gas supply stem ranges from 2 mm to 80 mm. In some examples, the outer diameter of the gas supply stem ranges from 25 mm to 150 mm. In some examples, the inner or outer diameter of the stem may or may not be cylindrical, or may or may not be circular in a cylindrical contour.

[0038] Some examples include methods. Referring to Figure 8, the method 800 for processing a substrate includes, in operation 802, providing a faceless shower head comprising a body including a back plate but not a face plate or plenum, a gas supply stem for introducing gas into the shower head, and a baffle supported away from the end of the gas supply stem; in operation 804, placing the faceless shower head in a substrate processing chamber; in operation 806, introducing gas into the processing chamber through the faceless shower head; and in operation 808, processing the substrate.

[0039] In some examples, the faceless shower head includes one or more features described in other parts of this specification. In some examples, method 800 further includes the step of generating plasma in a substrate processing chamber, or the step of not generating plasma in a substrate processing chamber.

[0040] While examples have been described with reference to specific exemplary embodiments or methods, it will be apparent that various modifications and changes may be made to these embodiments without departing from the broader definition of the embodiments. Therefore, the specification and drawings should be considered illustrative, not restrictive. The accompanying drawings, forming part of this application, illustrate, not restrictive, specific embodiments in which the subject matter of the invention may be carried out. The exemplary embodiments are described in sufficient detail to enable those skilled in the art to perform the teachings disclosed herein. Other embodiments may be used and derived from so that structural and logical substitutions and modifications may be made without departing from the scope of this disclosure. Therefore, the forms for carrying out the invention should not be taken restrictively, and the scope of various embodiments is defined solely by the appended claims and the entire scope of equivalent patented works relating such claims.

[0041] Even if one or more embodiments of the subject matter of the present invention are actually disclosed, they may be referred to individually and / or collectively as “the invention” for convenience only, and there is no intention to spontaneously limit the scope of this application to a single invention or inventive concept. Therefore, even if a particular embodiment is described and presented herein, it should be recognized that arrangements intended to achieve the same objective may be substituted for the specific embodiment shown. This disclosure is intended to include all adaptations or modifications of various embodiments. Combinations of the above embodiments with other embodiments not expressed herein will be apparent to those skilled in the art by reviewing the above description.

Claims

1. It is a faceless shower head, The main body includes a backplate but does not include a faceplate or plenum, A gas supply stem for introducing gas to the aforementioned faceless shower head, A baffle supported adjacent to the backplate or the gas supply stem, A faceless shower head equipped with this feature.

2. A faceless shower head according to claim 1, further, A faceless shower head comprising at least one support element for supporting the baffle in the baffle cavity within the back plate or the gas supply stem.

3. A faceless shower head according to claim 1, The diameter of the back plate is in the range of 12 mm to 105 mm, in a faceless shower head.

4. A faceless shower head according to claim 1, The baffle diameter is in the range of 2.5 mm to 13 mm, and it is a faceless shower head.

5. A faceless shower head according to claim 1, The baffle thickness is in the range of 0.5 mm to 3 mm, in a faceless shower head.

6. A faceless shower head according to claim 1, A faceless shower head in which the separation distance between the baffle and the back plate is in the range of 0.1 mm to 6 mm.

7. A faceless shower head according to claim 1, A faceless shower head in which the separation distance between the baffle and the gas supply stem is in the range of 0.5 mm to 6 mm.

8. A faceless shower head according to claim 1, The baffle includes an arrangement of one or more through holes, the diameter of which is in the range of 0.2 mm to 10 mm, in a faceless shower head.

9. A faceless shower head according to claim 8, In some examples, the diameter of the inner or outer circular pattern of the through-hole arrangement is in the range of 2 mm to 100 mm, in a faceless shower head.

10. A faceless shower head according to claim 2, A faceless shower head in which the diameter of the support element is in the range of 1 mm to 10 mm, and the length of the support element is in the range of 0.5 mm to 6 mm.

11. A method for processing a substrate, A step of providing a faceless shower head, wherein the faceless shower head includes a body that includes a back plate but does not include a face plate or plenum, a gas supply stem for introducing gas into the faceless shower head, and a baffle supported away from the end of the gas supply stem. The steps include installing the faceless shower head in the substrate processing chamber, A step of introducing gas into the processing chamber through the faceless shower head, The process of processing the substrate, Methods that include...

12. The method according to claim 11, The method comprising the faceless shower head having one or more features described in claims 2 to 10.

13. The method according to claim 11, further, A method comprising the step of generating plasma in the substrate processing chamber.

14. The method according to claim 11, further, A method comprising the step of not generating plasma in the substrate processing chamber.

Images