WO2023064128A1

WO2023064128A1 - Deposition chamber system diffusers with embedded thermocouple regions

Info

Publication number: WO2023064128A1
Application number: PCT/US2022/045446
Authority: WO
Inventors: Jong Yun Kim; William Nehrer; Sang Jeong Oh; Won Ho Sung; Sang Hoon Lee
Original assignee: Applied Materials, Inc.
Priority date: 2021-10-12
Filing date: 2022-09-30
Publication date: 2023-04-20
Also published as: TW202325101A

Abstract

An apparatus includes a diffuser including a plurality of opening structures. Each opening structure of the plurality of opening structures includes a respective pinhole of a plurality of pinholes. The apparatus further includes a thermocouple line embedded within the diffuser. The thermocouple line is disposed between a first pinhole of a first opening structure of the plurality of opening structures, and a second pinhole of a second opening structure of the plurality of opening structures.

Description

DEPOSITION CHAMBER SYSTEM DIFFUSERS WITH EMBEDDED

THERMOCOUPLE REGIONS

TECHNICAL FIELD

[0001] The instant specification generally relates to electronic device fabrication. More specifically, the instant specification relates to deposition chamber system diffusers with embedded thermocouple regions.

BACKGROUND

[0002] An electronic device manufacturing apparatus can include multiple chambers, such as process chambers and load lock chambers. Such an electronic device manufacturing apparatus can employ a robot apparatus in the transfer chamber that is configured to transport substrates between the multiple chambers. In some instances, multiple substrates are transferred together. [0003] Process chambers may be used in an electronic device manufacturing apparatus to perform one or more processes on substrates, such as deposition processes and etch processes. For many processes gases are flowed into the process chamber. Traditionally, the flow of process gases into process chambers is non-uniform. Such non-uniformity in the gas flow can cause some regions of substrates to be exposed to more process gases than other regions of the substrates. As a result, films resulting from the deposition and/or etch processes may be non-uniform.

SUMMARY

[0004] In accordance with an embodiment, an apparatus is provided. The apparatus includes a diffuser including a plurality of opening structures. Each opening structure of the plurality of opening structures includes a respective pinhole of a plurality of pinholes. The apparatus further includes a thermocouple line embedded within the diffuser. The thermocouple line is disposed between a first pinhole of a first opening structure of the plurality of opening structures, and a second pinhole of a second opening structure of the plurality of opening structures.

[0005] In accordance with another embodiment, a deposition chamber system is provided. The deposition chamber system includes a diffuser including a plurality of opening structures. Each opening structure of the plurality of opening structures includes a respective pinhole of a plurality of pinholes. The deposition chamber system further includes a thermocouple line embedded within the diffuser. The thermocouple line is disposed between a first pinhole of a first opening structure of the plurality of opening structures, and a second pinhole of a second opening structure of the plurality of opening structures. The deposition chamber system further includes a chamber body, a first insulator disposed between the diffuser and the chamber body, and a second insulator embedded within the chamber body adjacent to the first insulator.

[0006] In accordance with yet another embodiment, a method is provided. The method includes placing a thermocouple line within a first groove of a first plate, and securing the first plate to a second plate having a second groove to form a combined plate. The thermocouple line is housed within a region defined by the first groove and the second groove. The method further includes forming, from the combined plate, a diffuser including a plurality of opening structures and the thermocouple line embedded within the diffuser. Each opening structure of the plurality of opening structures includes a respective pinhole of a plurality of pinholes. The thermocouple lines is located between a first pinhole of a first opening structure of the plurality of opening structures, and a second pinhole of a second opening structure of the plurality of opening structures.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The present disclosure is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that different references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one. [0008] FIG. l is a cross-sectional view of a deposition chamber system for forming electronic devices, in accordance with some embodiments.

[0009] FIG. 2 is a top-down view of an example diffuser with an embedded thermocouple, in accordance with some embodiments.

[0010] FIG. 3 is a schematic of an example thermocouple, in accordance with some embodiments.

[0011] FIGS. 4A-4C are views of a portion of an example diffuser, in accordance with some embodiments.

[0012] FIGS. 5A-5F are cross-sectional views of an example process flow for fabricating a diffuser with an embedded thermocouple, in accordance with some embodiments.

[0013] FIGS. 6A-6B are cross-sectional views of a portion of a deposition chamber system, in accordance with some embodiments.

[0014] FIGS. 7A-7B are flow charts of example methods of fabricating a diffuser with an embedded thermocouple, in accordance with some embodiments. DETAILED DESCRIPTION

[0015] Processes for fabrication of electronic devices (e.g., semiconductor devices) generally include deposition of material (e.g., one or more thin film layers) on a substrate or wafer, and processing of the material. Deposition chamber systems, such as chemical vapor deposition (CVD) chamber systems, utilize process gases to perform a deposition process to deposit the material onto a substrate. Examples of CVD deposition processes include plasma enhanced (PE) CVD, thermally enhanced (TE) CVD, high density plasma (HDP) CVD, etc. To perform such CVD deposition processes, a substrate or wafer can be placed within a reactor chamber, and chemical vapors can be introduced into the reactor chamber that cause deposition of a particular material. For example, the particular material can be a dielectric material. One example of a dielectric material that can be deposited using a deposition process is a silicon oxide (SiOx).

[0016] Liquid crystal displays or flat panels are commonly used for active matrix displays such as computer monitors and television monitors. PECVD is generally employed to deposit thin films on a substrate, such as a transparent substrate for flat panel display or semiconductor wafer. PECVD is generally accomplished by introducing a precursor gas or gas mixture into a vacuum chamber that contains a substrate disposed on a temperature-controlled substrate support (e.g., susceptor). The gas mixture can include reactant gases that combine to form material on the substrate, and inert gases. The precursor gas or gas mixture is typically directed downwardly through a distribution plate situated near the top of the chamber. The gas mixture can be energized or excited into a plasma by applying radio frequency (RF) power to the chamber from one or more RF sources coupled to the chamber, where the excited inert gases can cause sputter etching of the material being formed on the substrate by the reactant gases. Thus, the combination of deposition and etching can be used to fill portions of a device (e g., a display device) with dielectric material. The deposition rate is directly related to the reactant gas flow rate, and the etch rate is directly related to the inert gas flow rate. However, the ratio between the deposition rate and the etch rate should be controlled to enable controlled dielectric material deposition and removal. This is particularly true as device features become smaller and have higher aspect ratios. To control the reactant gas flow rate and/or the inert gas flow rate, and thus the ratio between the deposition rate and the etch rate, a CVD deposition chamber can utilize a gas delivery system including a diffuser that functions to control the distribution of the reactant gases and/or inert gases, and gas lines that direct the reactant gases and/or inert gases into the reactor.

[0017] An organic light-emitting diode (OLED) can include anode, a cathode, and an organic light emitting layer between the anode and the cathode. Electron injection and hole injection into the organic light emitting layer can be performed through the cathode and the anode, respectively, in order to generate particles that emit light. An OLED device can be a display device including a number of OLEDs. Some OLED display devices use thin fdm transistor (TFT) display panels (e.g., the low temperature polysilicon (LTPS) TFT display panels). LTPS TFT display panels contribute to high display device production costs and power consumption. To address the drawbacks of LTPS TFT, low temperature polycrystalline oxide (LTPO) TFT display panels have been developed. The LTPO TFT display panel has similar properties to the LTPS TFT display panel (e.g., similar resolution, response speed, brightness, and aperture ratio), but with improvements to both production cost and power consumption. For example, silicon monoxide (SiO) and/or silicon dioxide (SiCh) (also referred to as silica) thin films can be deposited onto a display substrate to enable OLED surface passivation after the formation of an OLED cathode.

[0018] Flat panels for display devices processed by PECVD techniques can be large in area, often exceeding 4 square meters. Diffusers (e.g., gas distribution plates) utilized to provide uniform process gas flow over flat panels are relatively large in size, particularly as compared to diffusers utilized for semiconductor device wafer processing. Further, as the substrates used to form display devices are generally rectangular in shape, edges of the substrate, such as sides and comers thereof, experience conditions that may be different than the conditions experienced at other portions of the substrate. These different conditions affect processing parameters such as film thickness, deposition uniformity and/or film stress. Therefore, as the size of flat panel display substrates continues to grow, film thickness and film uniformity control for large area PECVD becomes an issue. For example, the difference of deposition rate and/or film property, such as film thickness or stress, between the center and the edges of the substrate becomes significant.

[0019] Process control problems such as THK drift, uniformity drift, zinc separation, etc. can be observed during deposition processes. Such process control problems may be related to diffuser temperature. Although temperature of some parts of the deposition chamber system can be measured for process control, diffusers may not have sensors for measuring diffuser temperature. Thus, such process control problems may not be able to be resolved systematically as it may not be possible to accurately measure the current diffuser temperature.

[0020] Aspects and implementations of the present disclosure address these and other shortcomings of existing technologies by providing for deposition chamber diffusers (“diffusers”) with embedded thermocouple regions. More specifically, the embedded thermocouple region can include a thermocouple line. For example, the thermocouple line can include a pair of thermocouple wires. The diffusers described herein can be implemented within any suitable deposition chamber system. In some embodiments, a diffuser is implemented within a plasma enhanced chemical vapor deposition system (PECVD) configured to process large area substrates (e.g., for fabrication of OLED displays). The material formed by the deposition chamber system can include a dielectric material (e.g., an oxide and/or a nitride). For example, the material can include a dielectric stack including pairs of alternating oxide and nitride layers, where each pair of layers is formed during a particular PECVD cycle. In some embodiments, the oxide layer can include a silicon oxide material (e.g., SiCh) and the nitride layer can include a silicon nitride material (e.g., SiN).

[0021] FIG. 1 is a cross-sectional view of a deposition chamber system 100 for forming electronic devices, in accordance with some embodiments. In this illustrative embodiment, the system 100 is a PECVD system. However, the system 100 is just an exemplary system that may be used to electronic devices on a substrate, and it contemplated that other deposition chambers may be utilized in accordance with the embodiments described herein.

[0022] The chamber 100 generally includes walls 102, a bottom 104, and a gas distribution plate or diffuser 110, and substrate support 130 which define a process volume 206. The process volume 106 is accessed through a sealable slit valve 108 formed through the walls 102 such that the substrate, may be transferred in and out of the chamber 100. The substrate support 130 includes a substrate receiving surface 132 for supporting a substrate 105 and stem 134 coupled to a lift system 136 to raise and lower the substrate support 130. A shadow frame 133 may be placed over periphery of the substrate 105 during processing. Lift pins 138 are moveably disposed through the substrate support 130 to move the substrate 105 to and from the substrate receiving surface 132 to facilitate substrate transfer. The substrate support 130 may also include heating and/or cooling elements 139 to maintain the substrate support 130 and substrate 105 positioned thereon at a desired temperature. The substrate support 130 may also include grounding straps 131 to provide RF grounding at the periphery of the substrate support 130.

[0023] The diffuser 110 is coupled to a backing plate 112 at its periphery by a suspension 114. The diffuser 110 may also be coupled to the backing plate 112 by one or more center supports 116 to help prevent sag and/or control the straightness/curvature of the diffuser 110. A gas source 120 is coupled to the backing plate 112 to provide gas through the backing plate 112 to a plurality of gas passages 111 formed in the diffuser 110 and to the substrate receiving surface 132. A vacuum pump 109 is coupled to the chamber 100 to control the pressure within the process volume 106. An RF power source 122 is coupled to the backing plate 112 and/or to the diffuser 110 to provide RF power to the diffuser 110 to generate an electric field between the diffuser 110 and the substrate support 130 so that a plasma may be formed from the gases present between the diffuser 110 and the substrate support 130. Various RF frequencies may be used, such as a frequency between about 0.3 MHz and about 200 MHz. In one embodiment, the RF power source 122 provides power to the diffuser 110 at a frequency of 13.56 MHz.

[0024] A remote plasma source 124, such as an inductively coupled remote plasma source, may also be coupled between the gas source 126 and the backing plate 112. Between processing substrates, a cleaning gas may be provided to the remote plasma source 124 and excited to form a remote plasma from which dissociated cleaning gas species are generated and provided to clean chamber components. The cleaning gas may be further excited by the RF power source 122 provided to flow through the diffuser 110 to reduce recombination of the dissociated cleaning gas species. Suitable cleaning gases include but are not limited to NF3, F2, and SFe.

[0025] In one embodiment, the heating and/or cooling elements 139 may be utilized to maintain the temperature of the substrate support 130 and substrate 105 thereon during deposition less than about 400 degrees Celsius or less. In one embodiment, the heating and/or cooling elements 139 may be used to control the substrate temperature to less than 100 degrees Celsius, such as between 20 degrees Celsius and about 90 degrees Celsius.

[0026] The spacing during deposition between a top surface of the substrate 105 disposed on the substrate receiving surface 132 and a bottom surface 140 of the diffuser 110 may be between 400 mil and about 1,200 mil, for example between 400 mil and about 800 mil. In one embodiment, the bottom surface 140 of the diffuser 110 may include a concave curvature wherein the center region is thinner than a peripheral region thereof, as shown in the cross- sectional view of Figure 1.

[0027] The chamber 100 may be used to deposit silicon oxide (SiOx) with silane (SiH4) gas diluted in nitrous oxide (N2O) by a PECVD process which is widely used as gate insulator films, buffer layer for heat dissipation and etch stop layers in TFT’s and AMOLED’s. The uniformity (i.e., thickness) of the oxide film has significant impact on the final device performance, such as mobility and drain current uniformity, and therefore is critical in the development of the process. A film uniformity of about 5%, or less, across the surface of the substrate, as well as minimal edge exclusion, is desired. While many strides have been made toward this goal, there are regions of the substrate where this uniformity is not achieved. For example, edges of the substrate, such as corner regions and sides of the substrate, experience a lower deposition rate which results in film thicknesses at these regions that are less than other regions. Although not wishing to be bound by theory, the cause of the lower deposition rate in the edge regions is attributed to electromagnetic field variations and/or gas distribution adjacent these areas. An inventive diffuser 110 has been developed and tested to overcome these effects and minimize non-uniformities in films formed on the substrate 105.

[0028] FIG. 2 is a top-down view of an example diffuser 200 with an embedded thermocouple, in accordance with some embodiments. The diffuser 200 includes a perforated area 210. A number of opening structures are formed within the perforated area 210, including opening structures 215. Only a portion of the opening structures of the diffuser 200 are shown for simplicity. Sets of thermocouples 220-1 and 220-2 are attached to respective locations of the diffuser 200. The sets of thermocouples 220-1 and 220-2 collectively form an embedded thermocouple to monitor the temperature of the diffuser spatially and temporally. In this illustrative example, 5 thermocouples are inside of the perforated area 210 and 4 thermocouples are outside of the perforated area 210, where the thermocouples are located at respective locations along diagonals through the center of the diffuser 200. For example, thermocouples from the sets 220-1 and 220-2 are at locations indicated by circles 230-1 through 230-5.

[0029] FIG. 3 is a schematic of an example thermocouple 300, in accordance with some embodiments. As shown, the thermocouple 300 can include a voltage junction 310, a voltage junction 320 and a voltage junction 330. A pair of electrodes 340-1 and 340-2 can operatively couple the temperature sensor voltage junction 310 to the temperature reference voltage junction 320. A pair of conductive lines 350-1 and 350-2 can operatively couple the temperature reference voltage junction 320 to the temperature measurement voltage junction 330. For example, the electrode 340-1 can be a positive conductor, and the electrode 340-2 can be a negative conductor. Each of the conductive lines 350-1 and 350-2 can include the same conductive material. For example, each of the conductive lines 350-2 and 350-2 can include copper (Cu). However, each of the conductive lines 350-1 and 350-2 can include any suitable material in accordance with embodiments described herein.

[0030] The thermocouple 300 operates by exploiting the thermoelectric effect to convert voltage differences to a temperature measurement. More specifically, the thermocouple can harness the Seebeck effect, which is the electromotive force (emf) that develops across two points of an electrically conducting material when there is a temperature difference between them. Thus, the thermocouple 300 can generate a temperature-dependent voltage measurement that can be converted into a temperature measurement.

[0031] More specifically, the thermocouple 300 can be used to determine the temperature of an object at a point of measurement (Tsense) measured at the voltage junction 310. For example, a point of measurement can be one of the locations 230-1 through 230-5 described above with reference to FIG. 2. To do so, a reference temperature (T_ref) can be set with respect to the voltage junction 320, and a voltmeter 332 of the voltage junction 330 can be used to measure a voltage (V).

[0032] The measured voltage V can be determined based on the difference between the voltage contribution due to the electrode 340-1 (i.e., the change from Tsense to Tref) and the voltage contribution due to the electrode 340-2 (i.e., the change from Tref to Tsense). For example, V = f ^sense(S₊(T) — S_(T)) dT, where S₊ and S_ are Seebeck coefficients (i.e., thermoelectric sensitivity) of the electrodes 340-1 and 340-2, respectively. The voltage contribution due to the conductive line 350-1 (i.e., the change from Tref to the temperature associated with the voltage junction 330 (e.g., the voltmeter) (“Tmeter”)) cancels out the voltage contribution due to the conductive line 350-2 (i.e., the change from Tmeter to Tref) since conductive lines 350-1 and 350-2 include the same material. The temperature at the voltage junction 320, Tref, is known. For example, the voltage junction 320 can be cooled so that Tref is 0 °C. As another example, a temperature sensor can be used to measure the temperature of the voltage junction 320.

[0033] Tsense can be determined using the equation E(Tsense) — V + E(Tref), where EQ is the characteristic function. V + E(Tref) can be computed using the V and Tref described above. In other words, the goal is to identify a Tsense value that, when input into the characteristic function, yields V + E(Tref). For example, E(T) = J^T(S₊(T') — S_(T')) dT' + C, where C is the integration constant. C can be selected such that E(0) = 0.

[0034] The electrodes 340-1 and 340-2 can include any suitable conductive material in accordance with embodiments described herein. In some embodiments, the thermocouple 300 is a nickel -alloy thermocouple. More specifically, at least one of the electrodes 340-1 or 340-2 includes a nickel alloy. For example, the electrode 340-1 can include a nickel-chromium alloy (e.g., chromel®) and the electrode 340-2 can include a nickel-aluminum alloy (e.g., alumel®). The thermocouple 300 can be referred to as a Type K thermocouple.

[0035] As another example, the electrode 340-1 can include a nickel-chromium alloy (e.g., chromel®) and the electrode 340-2 can include a nickel-copper alloy. For example, the nickelcopper alloy can be constantan®. Alternatively, the electrode 340-2 can include a nickel- manganese-copper alloy (e.g., manganin®). The thermocouple 300 can be referred to as a Type E thermocouple.

[0036] As yet another example, the electrode 340-1 can include iron (Fe) and the electrode 340-2 can include a nickel-copper alloy (e.g., constantan®). The thermocouple 300 can be referred to as a Type J thermocouple. [0037] As yet another example, the electrode 340-1 can include a nickel-molybdenum alloy and the electrode 340-2 can include a nickel-cobalt alloy. The thermocouple 300 can be referred to as a Type M thermocouple. In some embodiments, the nickel-molybdenum alloy has an atomic percentage (at.%) of nickel (Ni) between about 75 and about 85, and an at.% of molybdenum (Mo) between about 25 and about 15. For example, the nickel-molybdenum alloy can be 82 at.% Ni and about 18 at.% Mo In some embodiments, the nickel-cobalt alloy has an at.% of Ni between about 90 and about 100, and an at.% of cobalt (Co) between about 0 and about 10. For example, the nickel-molybdenum alloy can be about 99.2 at.% Ni and about 0.8 at.% Co.

[0038] As yet another example, the electrode 340-1 can include a nickel-chromium-silicon alloy (e.g., nicrosil) and the electrode 340-2 can include a nickel-silicon alloy (e.g., nisil). The thermocouple 300 can be referred to as a Type N thermocouple.

[0039] As yet another example, the electrode 340-1 can include copper (Cu) and the electrode 340-2 can include a nickel-copper-alloy (e.g., constantan®). The thermocouple 300 can be referred to as a Type T thermocouple.

[0040] In some embodiments, the thermocouple 300 is a platinum-based thermocouple. More specifically, at least one of the electrodes 340-1 or 340-2 can include platinum (Pt) or a Pt alloy. In some embodiments, the Pt alloy is a platinum-rhodium alloy. In some embodiments, the Pt alloy is a platinum-molybdenum alloy.

[0041] For example, the electrode 340-1 can include a first platinum-rhodium alloy and the electrode 340-2 can include a second platinum-rhodium alloy. In some embodiments, the first platinum-rhodium alloy has an at.% of Pt between about 60 and about 80, and an at.% of rhodium (Rh) between about 20 and about 40. For example, the first platinum-rhodium alloy can be about 70 at.% Ni and about 30 at.% Rh. In some embodiments, the second platinum-rhodium alloy has an at.% of Pt between about 85 and about 99, and an at.% of Rh between about 1 and about 15. For example, the second platinum-rhodium alloy can be about 94 at.% Pt and about 6 at.% Rh. The thermocouple 300 can be referred to as a Type B thermocouple.

[0042] As another example, the electrode 340-1 can include a platinum-rhodium alloy and the electrode 340-2 can include Pt. In some embodiments, first platinum-rhodium alloy has an at.% of Pt between about 75 and about 95, and an at.% of rhodium (Rh) between about 5 and about 25. For example, the platinum-rhodium alloy can be about 87 at.% Ni and about 13 at.% Rh. The thermocouple 300 can be referred to as a Type R thermocouple. As another example, the platinum-rhodium alloy can be about 90 at.% Ni and about 10 at.% Rh. The thermocouple 300 can be referred to as a Type S thermocouple. [0043] In some embodiments, the thermocouple 300 is a tungsten-based thermocouple. More specifically, at least one of the electrodes 340-1 or 340-2 can include tungsten (W) or a W alloy. In some embodiments, the W alloy is a tungsten-rhenium alloy.

[0044] For example, the electrode 340-1 can include a first tungsten-rhenium alloy and the electrode 340-2 can include a second tungsten-rhenium alloy. In some embodiments, the first tungsten-rhenium alloy has an at.% of W between about 85 and about 99, and an at.% of rhenium (Re) between about 1 and about 15. In some embodiments, the second tungsten-rhenium alloy has an at.% of Pt between about 50 and about 80, and an at.% of Rh between about 20 and about 50. For example, the first tungsten-rhenium alloy can be about 95 at.% W and about 5 at.% Re. and the second tungsten-rhenium alloy can be about 74 at.% W and about 26 at.% Re. The thermocouple 300 can be referred to as a Type C thermocouple. As another example, the first tungsten-rhenium alloy can be about 97 at.% W and about 3 at.% Re. and the second tungsten- rhenium alloy can be about 75 at.% W and about 25 at.% Re. The thermocouple 300 can be referred to as a Type D thermocouple.

[0045] As another example, the electrode 340-1 can include W and the electrode 340-2 can include a tungsten-rhenium alloy. In some embodiments, the second tungsten-rhenium alloy has an at.% of Pt between about 50 and about 80, and an at.% of Rh between about 20 and about 50. For example, the second tungsten-rhenium alloy can be about 74 at.% W and about 26 at.% Re. The thermocouple 300 can be referred to as a Type G thermocouple.

[0046] Other types of thermocouples are possible. For example, the thermocouple 300 can be a noble-metal alloy-based thermocouple (e.g., Type P thermocouple). As another example, the thermocouple 300 can be an iridium-rhodium based thermocouple (e.g., one electrode 340-1 or 340-2 includes an iridium alloy and the other electrode 340-1 or 340-2 includes a rhodium alloy). [0047] The choice of materials used to form the electrodes 340-1 and 340-2 (i.e., type of thermocouple) can depend on a set of parameters, such as operating temperature or temperature range, desired sensitivity (e.g., microvolts per °C (pV/°C)), inertness, cost, etc.

[0048] FIG. 4A is a cross-sectional view of a portion of an example diffuser 400, in accordance with some embodiments. The diffuser 400 can include multiple opening structures, such as the opening structures 215 described above with reference to FIG. 2. The diffuser 400 includes a first opening structure 215-1 and a second opening structure 215-2. More specifically, the first opening structure 215-1 includes a first opening portion 410-1, a second opening portion 420-1, and a pinhole 430-1, and the second opening structure 215-2 includes a first opening portion 420-1, a second opening portion 420-2, and a pinhole 430-2. The geometry of the opening structures shown in FIG. 4 should not be considered limiting. [0049] The length of the first openings 410-1 and 410-2 is indicated by length “DI”. In some embodiments, DI can range from about 20 millimeters (mm) to about 30 mm. For example, DI can be about 25 mm. The length of the second openings 420-1 and 420-2 is indicated by length “D2”. In some embodiments, D2 can range from about 5 mm to about 15 mm. For example, D2 can be about 10 mm. The length of the pinholes is indicated by length “D3”. In some embodiments, D3 can range from about 1 mm to about 5 mm. For example, D3 can be about 3 mm. A total length of an opening structure is indicated by length “D4”. In some embodiments, D4 can range from about 26 mm to about 50 mm. For example, D4 can be about 38 mm.

[0050] As further shown, a thermocouple line 440 is formed within an embedded thermocouple region of the diffuser 400 between the pinholes 430-1 and 430-2. It is assumed that the thermocouple line 400 is going into/out of the page in the cross-sectional view, where the pinhole layer including pinholes 430-1 and 430-2 is the safety zone for the thermocouple line 440 to pass through. The diameter of the thermocouple line 440 is shown as being equal to the length of the pinholes 430-1 and 430-2 (i.e., D3). The thermocouple line 440 can include a pair of thermocouple wires 442. In some embodiments, the length of the thermocouple line 440 ranges from about 2 mm to about 2.5 mm. For example, the length of the thermocouple line 440 can be about 2.3 mm. In some embodiments, the height of the thermocouple line 440 ranges from about 1.2 mm to about 1.6 mm. For example, the height of the thermocouple line 400 can be about 1.4 mm. If the available path width is 6.3 mm, D3 is 3 mm, the length of the thermocouple line 440 is 2.3 mm and the height of the thermocouple line 440 is 1.4 mm, then the machining tolerance with respect to the length can be + ⁶³^^2,3 _mm = + 2 mm and the machining tolerance with

3 -1 4 respect to the height can be ± — - — mm = ± 0.8 mm.

[0051] FIGS. 4B-4C are top-down views of a portion of the example diffuser 400, in accordance with some embodiments. The thermocouple region 440 can traverse along any suitable line 410 in the regions between opening structures 215. The opening structures 215 can be arranged such that a distance between the centers of a pair of opening structures is indicated by length “D5”. In some embodiments, D5 can range from about 4 mm to about 12 mm. For example, D5 can be about 8 mm. It can be shown by the Pythagorean Theorem that if D5 is 8 mm, then the total path width can be about 6.9 mm. If the pinhole size is 0.6 mm, then available path width can be about 6.3 mm (6.9 mm - 0.6 mm).

[0052] The opening structures 215 can include opening structures 215-1 through 215-3. The center of opening structure 215-3 can be located at about the midpoint between opening structure 215-1 and opening structure 215-2 (“% D5”). Moreover, each of the opening structures (e.g., opening structure 215-3) can have an opening width indicated by width “D6”. More specifically, D6 can be defined as the diameter of the opening structure 215-3. The distance between the center opening structure 215-3 and the center of opening structure 215-1 (or the center of opening structure 215-2) is indicated by distance “D7”. A right triangle can be formed, where one leg has length of about % D5, another leg has length D7, and the hypotenuse has length D5. Thus, D7 can be determined, using the Pythagorean theorem, as about D5. The distance between the boundary of opening structure 215-3 and the boundary of opening structure 215-1 (or the boundary of opening structure 215-2) is indicated by distance “D8”. For example, D8 can be determined as D7 - 2 — = D7 — D6.

2

[0053] FIGS. 5A-5F are cross-sectional views 500A-500F of an example process flow for fabricating a device 500 including a diffuser with an embedded thermocouple, in accordance with some embodiments. FIG. 5A shows an upper plate 510-1 and a lower plate 510-2. FIG. 5A further shows the formation of a groove 515-1 within the upper plate 510-1 and the formation of a groove 515-2 within the lower plate 510-2. The grooves 515-1 and 515-2 represent respective notched regions for housing a thermocouple line when the upper plate 510-1 and the lower plate 510-2 are secured together (e.g., forged together). The upper plate 510-1 and the lower plate 510- 2 can have any suitable heights in accordance with embodiments described herein. In some embodiments, the upper plate 510-1 has a height ranging from about 20 mm to about 30 mm and the lower plate 510-2 has a height ranging from about 8 mm to about 14 mm. For example, the upper plate 510-1 can have a height of about 26.5 mm and the lower plate 510-2 can have a height of about 11.5 mm.

[0054] FIG. 5B shows the placement of a thermocouple line 520 within the groove 515-2. The thermocouple line 520 can include a thermocouple wire. For example, the thermocouple line 520 can include a pair of thermocouple wires. The thermocouple line 520 can have any suitable type (e.g., open end, shell or insulation). The thermocouple line 520 can have a length ranging from about 2 mm to about 2.5 mm, and a height ranging from about 1.2 mm to about 1.6 mm. Further details regarding the thermocouple line 520 are described above with reference to FIGS. 2-4C.

[0055] FIG. 5C shows the securing of the upper plate 510-1 and the lower plate 510-2 to obtain combined plate (e.g., non- separatable plate), and the formation of a plurality of backside openings including backside openings 532-1 and 532-2 within a region of the combined plate corresponding to a backside of the diffuser, resulting in an intermediate structure 530. Securing the upper plate 510-1 and the lower plate 510-2 can include forging the upper plate 510-1 and the lower plate 510-2. For example, the forging can be performed using a high-pressure forging process. The plurality of backside openings including backside openings 532-1 and 532-2 can be formed using any suitable method. For example, the plurality of backside openings including backside openings 532-1 and 532-2 can be formed by drilling.

[0056] FIG. 5D shows cleaning and flipping of the intermediate structure 530 In this illustrative example, backside openings 532-1 and 532-2 maintain their relative orientations after the flipping (i.e., backside opening 532-1 is to the left of backside opening 532-2). In alternative embodiments, the backside openings 532-1 and 532-2 can change their relative orientations after the flipping (e.g., backside opening 532-1 can be to the right of backside opening 532-2).

[0057] FIG. 5E shows the formation of a plurality of frontside openings including frontside openings 542-1 and 542-2 formed within a region corresponding to a frontside of the diffuser, resulting in an intermediate structure 540. The plurality of frontside openings including frontside openings 542-1 and 542-2 can be formed by drilling. The plurality of frontside openings including frontside openings 542-1 and 542-2 are formed to provide a hollow cathode effect (HCE) with respect to plasma distribution.

[0058] FIG. 5F shows the formation of a plurality of pinholes including pinholes 552-1 and 552-2 formed through the frontside openings, resulting in a diffuser structure 550. The diffuser structure 550 includes a plurality of opening structures, where each opening structure includes a respective backside opening, a respective frontside opening, and a respective pinhole that connects the backside opening and the frontside opening. For example, a first opening structure includes the backside opening 532-1, the frontside opening 542-1 and the pinhole 552-1, and a second opening structure includes the backside opening 532-2, the frontside opening 542-2 and the pinhole 552-2. Further details regarding the device 500 are described above with reference to FIGS. 1-4C.

[0059] FIGS. 6A and 6B are cross-sectional views of a portion of a deposition chamber system (“system”) 600, in accordance with some embodiments. As shown in FIG. 6A, the system 600 includes a pair of thermocouple wires, including a first thermocouple wire 610-1 and a second thermocouple wire 610-2, embedded within a diffuser 620. The diffuser 620 can include a diffuser structure, shown in this example as the diffuser structure 550 of FIG. 5D. A circled region 630 indicates a portion of the system 600, which is illustrated in FIG. 6B. As shown in FIG. 6B, the system 600 further includes a backing plate 640, a chamber body 650, insulators 660-1 through 660-3, and sealing structures including sealing structure 670 (e.g., O-rings). The insulator 660-1 is disposed between the diffuser 620 and the chamber body 650, and the insulator 660-2 is embedded within the chamber body 650 adjacent to the insulator 660-1. The thermocouple wire 610-2 traverses through the diffuser 620, the insulator 660-1 and the insulator 660-2, and exits the insulator 660-2. The second thermocouple wire 610-2 can have branches 612-1 through 612-5. Although 5 branches are shown, the number of branches should not be considered limiting. RF leakage through the thermocouple wires 610-1 and 610-2 can be protected by using high permeability and high inductance material for the thermocouple shielding material (e.g., Ni). The thermocouple wires 610-1 and 610-2 can be of any type. Example types include open end, shell and insulation.

[0060] FIG. 7A is a flow chart of an example method 700 of fabricating a diffuser with an embedded thermocouple, in accordance with some embodiments. At block 710, a first groove is formed in a first plate and a second groove is formed in a second plate. For example, the first plate can be a lower plate and the second plate can be an upper plate. In some embodiments, the first groove and the second groove are each a respective notched region. Further details regarding block 710 are described above with reference to FIG. 5A.

[0061] At block 720, a thermocouple line is placed within the first groove. The thermocouple line can include a thermocouple wire. For example, the thermocouple line can include a pair of thermocouple wires (e.g., a first thermocouple wire and a second thermocouple wire). The thermocouple line can have any suitable type (e.g., open end, shell or insulation). The thermocouple line can have a length ranging from about 2 mm to about 2.5 mm, and a height ranging from about 1.2 mm to about 1.6 mm. Further details regarding block 720 are described above with reference to FIG. 5B.

[0062] At block 730, the first plate is secured to the second plate to form a combined plate. More specifically, the thermocouple line can be housed in a region within the combined plate defined by the first groove and the second groove. For example, the combined plate can be a non- separatable plate. In some embodiments, securing the first plate to the second plate can include forging the first plate to the second plate. For example, the forging can include a high-pressure forging process. Further details regarding block 730 are described above with reference to FIG.

5C

[0063] At block 740, a diffuser is formed from the combined plate. More specifically, the diffuser can include a plurality of opening structure and the thermocouple line embedded within the diffuser. Each opening structure of the plurality of opening structures can include a respective pinhole of a plurality of pinholes. The thermocouple line can be located between a first pinhole of a first opening structure of the plurality of opening structures, and a second pinhole of a second opening structure of the plurality of opening structures. Each pinhole of the plurality of pinholes can have a length ranging from about 1 mm to about 5 mm Further details regarding block 740 are described above with reference to FIGS. 5C-5F, and will now be described in further detail below with reference to FIG. 7B.

[0064] FIG. 7B is a flow chart of an example method 740 of forming a diffuser from an upper plate and a lower plate, in accordance with some embodiments. At block 742, a plurality of backside openings is formed to obtain a first intermediate structure. More specifically, the first intermediate structure can be formed from a combined plate (e.g., the combined plate formed at block 730 as described above with reference to FIG. 7A). Each backside opening of the plurality of backside openings corresponds to a respective opening structure of the plurality of opening structures. The plurality of backside openings corresponds to a backside of the diffuser. For example, forming the plurality of backside openings can include drilling the plurality of backside openings. Further details regarding block 742 are described above with reference FIG. 5C.

[0065] At block 744, the first intermediate structure is flipped. In some embodiments, the first intermediate structure is cleaned prior to being flipped. In some embodiments, the first intermediate structure is cleaned after being flipped. Thus, the first intermediate structure can be cleaned after being formed. Further details regarding block 744 are described above with reference to FIG. 5D.

[0066] At block 746, a plurality of frontside openings is formed to obtain a second intermediate structure. More specifically, the plurality of frontside openings is formed within the first intermediate structure. Each frontside opening of the plurality of frontside openings corresponds to a respective opening structure of the plurality of opening structures. The plurality of frontside openings corresponds to a frontside of the diffuser. In some embodiments, the plurality of frontside openings is formed to provide a hollow cathode effect with respect to plasma distribution. For example, forming the plurality of frontside openings can include drilling the plurality of frontside openings. Further details regarding block 746 are described above with reference to FIG. 5E.

[0067] At block 748, a plurality of pinholes is formed. More specifically, forming the plurality of pinholes can include forming, through each frontside opening of the plurality of frontside, a respective pinhole of the plurality of pinholes. For example, forming the plurality of pinholes can include drilling the plurality of pinholes. Each pinhole of the plurality of pinholes can have a length ranging from about 1 mm to about 5 mm. Further details regarding block 748 are described above with reference to FIG. 5F.

[0068] The preceding description sets forth numerous specific details such as examples of specific systems, components, methods, and so forth, in order to provide a good understanding of several embodiments of the present invention. It will be apparent to one skilled in the art, however, that at least some embodiments of the present invention may be practiced without these specific details. In other instances, well-known components or methods are not described in detail or are presented in simple block diagram format in order to avoid unnecessarily obscuring the present invention. Thus, the specific details set forth are merely exemplary. Particular implementations may vary from these exemplary details and still be contemplated to be within the scope of the present invention.

[0069] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrase “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. In addition, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” When the term “about” or “approximately” is used herein, this is intended to mean that the nominal value presented is precise within ±10%. [0070] Although the operations of the methods herein are shown and described in a particular order, the order of the operations of each method may be altered so that certain operations may be performed in an inverse order or so that certain operation may be performed, at least in part, concurrently with other operations. In another embodiment, instructions or suboperations of distinct operations may be in an intermittent and/or alternating manner.

[0071] It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other implementation examples will be apparent to those of skill in the art upon reading and understanding the above description. Although the present disclosure describes specific examples, it will be recognized that the systems and methods of the present disclosure are not limited to the examples described herein, but may be practiced with modifications within the scope of the appended claims. Accordingly, the specification and drawings are to be regarded in an illustrative sense rather than a restrictive sense. The scope of the present disclosure should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

CLAIMS What is claimed is:

1. An apparatus comprising: a diffuser comprising a plurality of opening structures, each opening structure of the plurality of opening structures comprising a respective pinhole of a plurality of pinholes; and a thermocouple line embedded within the diffuser, the thermocouple line being disposed between a first pinhole of a first opening structure of the plurality of opening structures, and a second pinhole of a second opening structure of the plurality of opening structures.

2. The apparatus of claim 1, wherein each opening structure of the plurality of opening structures comprises a backside opening corresponding to a backside of the diffuser and a frontside opening corresponding to a frontside of the diffuser, and wherein each pinhole of the plurality of pinholes is disposed between a respective backside opening and a respective frontside opening.

3. The apparatus of claim 2, wherein the plurality of frontside openings provide a hollow cathode effect with respect to plasma distribution.

4. The apparatus of claim 1, wherein each pinhole of the plurality of pinholes can have a length ranging from about 1 millimeter (mm) to about 5 mm.

5. The apparatus of claim 1, wherein the thermocouple line comprises a pair of thermocouple wires.

6. The apparatus of claim 1, wherein the thermocouple line has a type selected from the group consisting of: open end, shell, and insulation.

7. The apparatus of claim 1, wherein the thermocouple line has a length ranging from about 2 millimeters (mm) to about 2.5 mm, and a height ranging from about 1.2 mm to about 1.6 mm.

8. A deposition chamber system comprising: a diffuser comprising a plurality of opening structures, each opening structure of the plurality of opening structures comprising a respective pinhole of a plurality of pinholes; a thermocouple line embedded within the diffuser, the thermocouple line being disposed between a first pinhole of a first opening structure of the plurality of opening structures, and a second pinhole of a second opening structure of the plurality of opening structures; a chamber body; a first insulator disposed between the diffuser and the chamber body; and a second insulator embedded within the chamber body adjacent to the first insulator.

9. The deposition chamber system of claim 8, wherein each opening structure of the plurality of opening structures comprises a backside opening corresponding to a backside of the diffuser and a frontside opening corresponding to a frontside of the diffuser, and wherein each pinhole of the plurality of pinholes is disposed between a respective backside opening and a respective frontside opening.

10. The deposition chamber system of claim 9, wherein the plurality of frontside openings provide a hollow cathode effect with respect to plasma distribution.

11. The deposition chamber system of claim 8, wherein each pinhole of the plurality of pinholes can have a length ranging from about 1 millimeter (mm) to about 5 mm.

12. The deposition chamber system of claim 8, wherein the thermocouple line comprises a pair of thermocouple wires.

13. The deposition chamber system of claim 8, wherein the thermocouple line has a type selected from the group consisting of: open end, shell, and insulation.

14. The deposition chamber system of claim 8, wherein the thermocouple line has a length ranging from about 2 millimeters (mm) to about 2.5 mm, and a height ranging from about 1.2 mm to about 1.6 mm.

15. A method compri sin : placing a thermocouple line within a first groove of a first plate; securing the first plate to a second plate having a second groove to form a combined plate, wherein the thermocouple line is housed within a region defined by the first groove and the second groove; and forming, from the combined plate, a diffuser comprising a plurality of opening structures and the thermocouple line embedded within the diffuser, each opening structure of the plurality of opening structures comprising a respective pinhole of a plurality of pinholes, wherein the thermocouple line is located between a first pinhole of a first opening structure of the plurality of opening structures, and a second pinhole of a second opening structure of the plurality of opening structures.

16. The method of claim 15, wherein forming the diffuser further comprises: forming, within the combined plate, a plurality of backside openings corresponding to a backside of the diffuser to obtain a first intermediate structure, each backside opening of the plurality of backside openings corresponding to a respective opening structure of the plurality of opening structures; after forming the first intermediate structure, flipping the first intermediate structure; and after flipping the intermediate structure, forming, within the first intermediate structure, a plurality of frontside openings corresponding to a frontside of the diffuser to obtain a second intermediate structure.

17. The method of claim 16, wherein forming the diffuser further comprises cleaning the first intermediate structure after forming the first intermediate structure.

18. The method of claim 16, wherein the plurality of frontside openings is formed to provide a hollow cathode effect with respect to plasma distribution.

19. The method of claim 16, wherein forming the diffuser further comprises forming, through each frontside opening of the plurality of frontside openings, a respective pinhole of the plurality of pinholes.

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20. The method of claim 15, wherein the thermocouple line comprises a pair of thermocouple wires.

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