Method for depositing high quality PVD films

Abstract

The present disclosure relates to methods for depositing high quality PVD films. Embodiments described herein include methods for depositing a material layer on a substrate while controlling the arcuate curvature of the substrate and the surface roughness of the material layer. A bias voltage applied to the substrate when depositing the material layer is adjusted to control arcuate bending of the substrate. A bombardment process is performed on the material layer to improve surface roughness of the material layer. The bias and bombardment process improves the uniformity of the material layer and reduces the occurrence of material layer cracking caused by arcuate bending of the substrate.

Description

[0001] This application is a divisional application of the invention patent application with application date of September 10, 2020, application number 202080074677.3, and invention name “Method for depositing high-quality PVD films”.

[0002] background

[0003] field

[0004] Embodiments of the present disclosure relate generally to methods for processing substrates, and more particularly, to methods of depositing films on substrates having reduced substrate bow and improved film quality. Background Art

[0005] Aluminum nitride (AlN) films are often deposited on substrates using physical vapor deposition (PVD). In certain applications, high crystal quality is desired for the AlN film. In order to achieve high quality films, the thickness of the AlN film is usually relatively large. For example, the thickness of the AlN film is usually between about 300 nm and about 2 microns. However, other problems arise when using films of this thickness. For example, thick AlN films cause the substrate to bow, resulting in cracking of the film. The bowing of the substrate can also affect subsequent processing of the substrate. For example, the bowing of the substrate can cause uneven light distribution during the photolithography process.

[0006] Therefore, there is a need for improved techniques for depositing films. Summary of the invention

[0007] In one embodiment, a method for depositing a material on a substrate is provided. The method includes depositing a material layer on the substrate. The method also includes adjusting a bias voltage applied to the substrate while depositing the material layer, the bias voltage controlling a bow-shaped bend of the substrate. The method also includes performing a bombardment process on the material layer.

[0008] In another embodiment, a method for depositing a material on a substrate is provided. The method sequentially includes adjusting a bias voltage applied to the substrate while depositing a material layer on the substrate, the bias voltage being between about 30 W and about 80 W, and performing a bombardment process on the material layer.

[0009] In another embodiment, a method for processing a substrate is provided. The method includes depositing a material layer on a substrate disposed in a process chamber. The method also includes adjusting a bias voltage applied to the substrate during the deposition of the material layer. The method also includes generating an argon plasma and bombarding the material layer with the argon plasma. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In this manner, the above-mentioned features of the present disclosure can be understood in detail, and a more particular description of the present disclosure briefly summarized above can be obtained by reference to the embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the drawings illustrate only exemplary embodiments and therefore should not be considered to limit the scope of the present disclosure, as the present disclosure may admit to other equally effective embodiments.

[0011] Figure 1 Operations of a method for depositing a film on a substrate are illustrated according to certain embodiments.

[0012] Figure 2A is a graph illustrating data representing substrate bow after depositing a material layer on the substrate, according to certain embodiments.

[0013] Figure 2B is a graph illustrating data representing substrate bow after depositing a material layer on the substrate, according to certain embodiments.

[0014] Figure 3 is a graph illustrating data representing the measured quality of a layer of material after being deposited on a substrate, according to certain embodiments.

[0015] Figure 4 is a graph illustrating data representing substrate bow after deposition on the substrate, according to certain embodiments.

[0016] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is understood that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation. DETAILED DESCRIPTION

[0017] Embodiments described herein include methods for depositing a material layer on a substrate while controlling the bow of the substrate and the surface roughness of the material layer. A bias voltage applied to the substrate while depositing the material layer is adjusted to control the bow of the substrate. A bombardment process is performed on the material layer to improve the surface roughness of the material layer. The bombardment process and the bias voltage respectively improve the surface roughness of the material layer and reduce the occurrence of cracks in the material layer caused by the bow of the substrate.

[0018] In one embodiment, physical vapor deposition (PVD) may be used to deposit the material layer. During the deposition operation, the substrate is disposed on a substrate support pedestal. In one embodiment, the substrate support pedestal is an electrostatic chuck. A first electrode is disposed in the substrate support pedestal and provides an adsorption force to the substrate. A second electrode is disposed in the pedestal and provides a bias voltage to a surface of the substrate opposite the pedestal. The bias voltage applied to the substrate at least partially controls the bowing of the substrate caused by the deposition operation.

[0019] Figure 1The operations of a method 100 for depositing a film on a substrate are illustrated according to certain embodiments. At operation 102, a physical vapor deposition (PVD) process is performed to deposit a material on the substrate. The PVD process includes sputtering a material from a sputtering target, and depositing the sputtered material onto the substrate. In one embodiment, the material deposited on the substrate is an aluminum nitride (AlN) layer.

[0020] In certain embodiments that may be combined with one or more of the embodiments discussed above, the material deposited on the substrate comprises a scandium-containing material. In certain embodiments that may be combined with one or more of the embodiments discussed above, the material layer comprises scandium at a concentration between about 1 atomic percent and about 25 atomic percent. For example, the material layer may comprise scandium at a concentration between about 1 atomic percent and about 10 atomic percent, or scandium at a concentration between about 10 atomic percent and about 25 atomic percent.

[0021] The thickness of the material layer deposited on the substrate is between about 200 nanometers and about 2,500 nanometers, for example, about 1 micron. In certain embodiments that may be combined with one or more embodiments described above, the PVD process is divided into more than one deposition operation. For example, the deposition operation may be repeated between about 4 times and about 30 times, for example between about 5 times and about 10 times, such as about 8 times. That is, the material layer may be a stacked structure of multiple, smaller layers that ultimately form the material layer.

[0022] The duration of the PVD process may depend on the number of deposition operations. For example, a material layer having a thickness of about 1.5 microns may be deposited by between about 20 and about 50 deposition operations, such as about 30 deposition operations. Each of the deposition operations may have a duration between about 30 seconds and about 80 seconds, such as between about 45 seconds and about 60 seconds, such as about 57 seconds. The power of the PVD process is between about 5 kW and about 8.5 kW, such as about 8 kW.

[0023] As another example, a layer of material having a thickness of about 200 nanometers may be deposited by between about 5 and about 10 deposition operations, such as about 8 deposition operations. Each of the deposition operations may have a duration between about 10 seconds and about 60 seconds, for example between about 15 seconds and about 30 seconds, such as about 25 seconds. Any particular deposition operation may have a longer or shorter duration than a previous or subsequent deposition operation. The thickness of the material deposited during each deposition operation may be different. For example, five deposition operations may deposit 5 nm of material, while eight subsequent deposition operations may deposit 20 nm of material.

[0024] While depositing material on the substrate, the substrate may bow (e.g., curve). In order to reduce the amount of substrate bowing, a bias is applied to the substrate during the deposition process. The bias may be applied to the substrate during each deposition operation. In one embodiment that may be combined with one or more embodiments discussed above, a single bias (e.g., 50 W) is applied to the substrate during each deposition operation. The same bias (e.g., 50 W) may be applied to the substrate during each deposition operation of the deposition operation.

[0025] In certain embodiments that may be combined with one or more of the above embodiments, a first bias value may be applied to the substrate during a first number of deposition operations, and a second bias value may be applied to the substrate during a second number of deposition operations. For example, a first bias of about 40 W is applied during the first 10 deposition operations, and a second bias of 60 W is applied during the subsequent 12 deposition operations.

[0026] In certain embodiments that may be combined with one or more embodiments described above, a bias voltage applied to a substrate may be determined based on a substrate bow caused by a previous deposition operation. For example, a first bias voltage applied to a substrate during a first deposition operation may cause substrate bowing. The substrate bowing is measured after the first deposition operation. A bias voltage applied to the substrate during a subsequent deposition operation may be determined based on the measured substrate bowing, such that the bias voltage applied during the subsequent operation offsets the measured substrate bowing. That is, after the subsequent deposition operation, the substrate bowing is negligible.

[0027] For example, a bias voltage (e.g., 40 W) that creates a concave substrate bow may be applied to the substrate after a deposition operation (e.g., 60 W) that creates a convex substrate bow. That is, the bias voltage applied to the substrate may reduce the substrate bow by applying a bow opposite to the bow caused by the previous deposition operation. The bias voltage applied to the substrate during the deposition operation may alternate between a bias voltage that creates a convex substrate bow and a bias voltage that creates a concave substrate bow. As a result, the bow of the substrate having a material layer deposited on the substrate is substantially reduced.

[0028] In certain embodiments that may be combined with one or more of the above embodiments, the bow of the substrate is known before depositing a material layer on the substrate. In this case, a bias voltage to achieve a suitable substrate bow can be determined based on the pre-existing bow of the substrate. For example, a bias voltage that causes a convex substrate bow can be applied to a substrate having a concave bow, so that the resulting bow of the substrate after depositing a material layer on the substrate is substantially neutral.

[0029] In certain embodiments that may be combined with one or more embodiments discussed above, the bias voltage applied during each deposition operation may be different from the bias voltage applied during the previous deposition operation. For example, the bias voltage during the first deposition operation may be about 0 W. The bias voltage may be increased for each subsequent deposition operation such that the bias voltage during the last deposition operation is about 100 W.

[0030] In certain embodiments that may be combined with one or more of the above embodiments, the bias voltage may be adjusted based on the thickness of the material deposited on the substrate. For example, the bias voltage may be increased as the thickness of the deposited material increases. As the thickness of the deposited material increases, a greater bias voltage may achieve a suitable substrate bowing profile.

[0031] In certain embodiments that may be combined with one or more embodiments described above, the bias voltage may be adjusted for each deposition operation based on a linear function. In other embodiments that may be combined with one or more embodiments described above, the bias voltage may be adjusted for each deposition operation based on a step function.

[0032] The average bias voltage applied to the substrate during operation 102 is between about 30 W and about 100 W, such as between about 50 W and about 75 W. The bias voltage applied to the substrate may be a continuous bias voltage or a pulsed bias voltage. During the processing of the substrate, the bias voltage applied to the substrate is automatically adjusted by the controller.

[0033] Advantageously, adjusting the bias voltage applied to the substrate controls the bow of the substrate. Adjusting the bias voltage changes the substrate bow from a tensile bow to a compressive bow. That is, a substantially neutral bow profile is achieved for a substrate having a material layer disposed on the substrate. By controlling the bow of the substrate, the occurrence of damage (e.g., cracking) to the material layer is reduced. The bow of the substrate may also affect subsequent processing of the substrate. For example, the bow of the substrate may result in uneven light distribution during a photolithography process. In addition, adjusting or regulating the substrate bias voltage does not degrade the quality (e.g., crystallinity) of the material layer.

[0034] The pressure used during the PVD process may be between about 1.5 mTorr and about 6.5 mTorr, for example between about 2 mTorr and about 3.5 mTorr, such as about 2.5 mTorr. The pressure may be adjusted to improve the surface roughness of the material layer.

[0035] At operation 104, an argon bombardment process is performed on the material layer deposited on the substrate. The argon bombardment process includes generating an argon plasma in a process chamber. The bombardment process is performed for between about 50 seconds and about 250 seconds, for example between about 100 seconds and about 200 seconds, such as about 150 seconds.

[0036] Advantageously, the bombardment process further improves the surface roughness of the deposited material layer without affecting the substrate bow or the crystallinity (ie, quality) of the material layer. The surface roughness of the material layer after the bombardment process is between about 1.10 nm and about 0.85 nm, for example about 0.99 nm.

[0037] In one embodiment that may be combined with one or more of the above embodiments, method 100 may be repeated. For example, operation 102 may be performed to deposit material on the substrate for between about 10 seconds and 30 seconds, for example between about 22 seconds and 28 seconds, such as about 25 seconds. The bombardment process of operation 104 may then be performed for between about 15 seconds and about 45 seconds, for example between about 20 seconds and 40 seconds, such as about 30 seconds. In this embodiment, method 100 may be repeated between about 5 times and about 10 times, such as about 8 times, such that the total deposition time of operation 102 is between about 50 seconds and about 300 seconds, such as about 200 seconds, and the total bombardment time of operation 104 is between about 75 seconds and about 450 seconds, such as about 240 seconds.

[0038] Figure 2A 2 is a graph 200 illustrating data showing substrate bowing after depositing a material layer on the substrate according to some embodiments. The material layer is deposited on the substrate by a deposition process such as a deposition process related to Figure 1 The deposition process discussed. Figure 2A The power of the deposition process is about 8 kW.

[0039] The thickness of the material layer deposited on the substrate corresponding to the substrate bow depicted in graph 200 is about 500 nm. The vertical axis of graph 200 corresponds to the substrate bow, and the horizontal axis is the position on the substrate from the center point of the substrate (Y=0 mm). Figure 2A No post-processing was performed on the material layers discussed.

[0040] A first line 252 on the graph 200 depicts a bow of a substrate having a layer of material deposited on the substrate. No bias was applied to the substrate corresponding to the first line 252 during processing. As depicted by the first line 252, the substrate has a convex bow, wherein an outer portion of the substrate (near the outer edge at about Y=±150 mm) bows in a direction toward the surface of the substrate having the layer of material deposited on the surface, and a central portion of the substrate (near the center of the substrate at about Y=0 mm) bows away from the surface having the layer of material deposited on the surface. As an example, the total resulting bow of the substrate corresponding to the first line 252 is between about 120 microns and about 180 microns, such as about 140 microns.

[0041] A second line 254 on the graph 200 depicts a bowed bend of a substrate having a material layer deposited thereon. The bias voltage applied to the substrate corresponding to the second line 254 during processing is higher than the bias voltage applied to the substrate corresponding to the first line 252. For example, the bias voltage applied to the substrate corresponding to the second line 254 is between about 10W and about 45W, such as about 40W.

[0042] As depicted by the second line 254, the corresponding substrate has a convex bow, wherein the outer portion of the substrate (approximately Y=±150 mm) is bowed toward the material layer deposited on the substrate, and the central portion of the substrate (approximately Y=0 mm) is bowed away from the material layer. The bow of the substrate corresponding to the second line 254 is less than the bow of the substrate corresponding to the first line 252. The total bow of the substrate corresponding to the second line 254 is between about 90 microns and about 120 microns, such as about 105 microns. That is, the bow of the substrate corresponding to the second line 254 is reduced by about 25 percent compared to the bow of the substrate corresponding to the first line 252.

[0043] A third line 256 on the graph 200 depicts a bowed bend of a substrate having a material layer deposited thereon. The bias voltage applied to the substrate corresponding to the third line 256 during processing is higher than the bias voltage applied to the substrate corresponding to the second line 254. For example, the bias voltage applied to the substrate corresponding to the third line 256 is between about 30W and about 55W, such as about 50W.

[0044] As depicted by the third line 256, the corresponding substrate has a convex bow (bowed away from the material layer) near the center of the substrate (Y=0 mm) and a concave bow (bowed toward the material layer) near the outer edge of the substrate (Y=±150 mm). The bow of the substrate corresponding to the third line 256 is less than (i.e., reduced) the bow of the substrate corresponding to the second line 254. For example, the bow of the substrate corresponding to the third line 256 is between about 10 microns and about 50 microns, such as about 20 microns. That is, the bow of the substrate corresponding to the third line 256 is reduced by about 80 percent compared to the bow of the substrate corresponding to the second line 254.

[0045] A fourth line 258 on the graph 200 depicts a bowed bend of a substrate having a material layer deposited thereon. The bias voltage applied to the substrate corresponding to the fourth line 258 during processing is higher than the bias voltage applied to the substrate corresponding to the third line 256. For example, the bias voltage applied to the substrate corresponding to the fourth line 258 is between about 50W and about 80W, such as about 60W.

[0046] As depicted by fourth line 258, the corresponding substrate has a concave bow, wherein a central portion of the substrate (close to the center of the substrate at Y=0 mm) bows toward the material layer, and an outer portion of the substrate (close to the outer edge of the substrate at Y=±150 mm) bows away from the material layer. The bow of the substrate corresponding to fourth line 258 is greater than the bow of the substrate corresponding to third line 256. However, the bow of the substrate corresponding to fourth line 258 is less than the bow of the substrate corresponding to first line 252 and second line 254.

[0047] The bias voltage applied to the substrate corresponding to the fourth line 258 causes an increase in the substrate bowing compared to the substrate bowing corresponding to the third line 256. For example, the substrate bowing corresponding to the fourth line 258 is between about 50 microns and about 150 microns, such as about 75 microns. Therefore, the substrate bowing corresponding to the fourth line 258 produces an increase of about 30 percent in the substrate bowing compared to the substrate corresponding to the third line 256. The fifth line 260 on the graph 200 depicts the bowing of the substrate having a material layer deposited on the substrate. The bias voltage applied to the substrate corresponding to the fifth line 260 during processing is higher than the bias voltage applied to the substrate corresponding to the fourth line 258. For example, the bias voltage applied to the substrate corresponding to the fifth line 260 is between about 65W and about 120W, such as about 100W.

[0048] As depicted by the fifth line 260, the corresponding substrate has a concave bow, wherein a central portion of the substrate (near the center of the substrate at Y=0 mm) bows toward the material layer, and an outer portion of the substrate (near the outer edge of the substrate at Y=±150 mm) bows away from the material layer. The bow of the substrate corresponding to the fifth line is greater than the bow of the substrate corresponding to the first line 252, the second line 254, the third line 256, and the fourth line 258. The maximum bow of the substrate corresponding to the fifth line 260 is about 375 microns.

[0049] Although the first line 252 and the second line 254 are illustrated as having a convex arcuate curvature, these lines may have a concave arcuate curvature depending on various parameters, such as the bias applied to the substrate or on which surface of the substrate the material layer is deposited. Similarly, the arcuate curvature of the substrate corresponding to the third line 256, the fourth line 258, and the fifth line 260 may be opposite to the arcuate curvature depicted in the diagram 200 and described above.

[0050] As illustrated in graph 200, adjusting the bias voltage applied to the substrate during deposition of the material layer controls the bow of the substrate. For example, as the bias voltage increases, the bow of the substrate decreases until a certain point, after which the bow of the substrate increases. Based on the above graph 200, during deposition of the material layer, the bias voltage that minimizes the bow of the substrate is applied to the substrate between about 40 W and about 60 W. The bias voltage that minimizes the bow of the substrate can vary due to various parameters, such as the thickness of the material layer deposited on the substrate during processing, the thickness of the material layer present on the substrate prior to the deposition operation of the bias voltage, and the like.

[0051] Figure 2B A graph 250 is illustrated showing data of minimum substrate bow after a material layer of a particular thickness is deposited on the substrate according to certain embodiments. The graph includes one or more lines 210-218, each line corresponding to a substrate having a material layer of a different thickness deposited on the substrate. As discussed below, the thickness of the material layer decreases from the first line 210 to the fifth line 218. The pressure of the deposition process for depositing the material layer is between about 4 mTorr and about 6 mTorr, such as about 5.2 mTorr. The vertical axis of the graph 250 corresponds to substrate bow in microns, and the horizontal axis corresponds to a position on the substrate from the outer edge of the substrate (Y=±150 mm) to the center point (Y=0 mm). About Figure 2B No post-processing was performed on the material layers discussed.

[0052] The first line 210 depicts the bow of a substrate having a material layer having a thickness of about 2500 nm deposited on the substrate. The bias voltage applied to the substrate during deposition of the material layer is between about 70 W and about 80 W, such as about 75 W. As depicted by the first line 210, the substrate has a convex bow near the center (Y=0 mm) and a concave bow near the edge at about Y=±125 mm.

[0053] The second line 212 depicts the bow of a substrate having a material layer having a thickness of about 1500 nm deposited on the substrate. The bias voltage applied to the substrate during deposition of the material layer is between about 65 W and about 75 W, such as about 70 W. As depicted by the second line 212, the corresponding substrate has a convex bow near the center (Y=0 mm) and a concave bow near the edge at about Y=±125 mm. The bow of the substrate corresponding to the second line 212 is reduced by about 50 percent compared to the substrate corresponding to the first line 210.

[0054] The third line 214 depicts the bow of a substrate having a material layer having a thickness of about 1000 nm deposited on the substrate. The bias voltage applied to the substrate during deposition of the material layer is between about 60 W and about 70 W, such as about 65 W. As depicted by the third line 214, the corresponding substrate has a convex bow near the center (Y=0 mm) and a concave bow near the edge at about Y=±125 mm. The bow of the substrate corresponding to the third line 214 is reduced by about 25 percent compared to the substrate corresponding to the second line 212.

[0055] The fourth line 216 depicts the bow of a substrate having a material layer having a thickness of about 400 nm deposited on the substrate. The bias voltage applied to the substrate during deposition of the material layer is between about 50 W and about 60 W, such as about 55 W. As depicted by the fourth line 216, the corresponding substrate has a convex bow near the center (Y=0 mm) and a concave bow near the edge at about Y=±125 mm. The bow of the substrate corresponding to the fourth line 216 is reduced by about 50 percent compared to the substrate corresponding to the third line 214.

[0056] The fifth line 218 depicts the bow of a substrate having a material layer having a thickness of about 200 nm deposited on the substrate. The average bias voltage applied to the substrate during deposition of the material layer is between about 45 W and about 55 W, such as about 50 W. As depicted by the fifth line 218, the corresponding substrate has a convex bow near the center (Y=0 mm) and a concave bow near the edge at about Y=±125 mm. The bow of the substrate corresponding to the fifth line 218 is reduced by about 70 percent compared to the substrate corresponding to the fourth line 216.

[0057] The combination of the thickness of the material layer and the bias voltage discussed above demonstrates that the bowing of the substrate can be adjusted using the bias voltage applied to the substrate during deposition of the material layer. Figure 2B As shown in FIG, the bow of the substrate can be influenced or adjusted using a bias voltage applied to the substrate during deposition of the material layer depending on the thickness of the material layer deposited on the substrate. For a material layer having a thickness of less than 2500 nm, the bow of the substrate in any direction can be maintained to less than about 100 microns.

[0058] Figure 3 3 is a graph 300 illustrating data representing the measured quality of a material layer after being deposited on a substrate according to certain embodiments. The quality of the material layer is measured along the AlN (002) crystal direction using an x-ray diffraction rocking curve scan. The material layer is deposited on the substrate by a deposition process such as that described above. Figure 1 , Figure 2A and Figure 2BThe deposition process discussed. The pressure of the deposition process for depositing the material layer on the substrate is between about 4 mTorr and about 6 mTorr, such as about 5.2 mTorr. The thickness of the material layer is about 2500 microns.

[0059] The first line 310, the second line 312, and the third line 314 represent the quality of the material layer at the center point of the substrate, about 70 mm from the center point, and near the edge, respectively. The full width at half maximum (FWHM) of the AlN (002) rocking curve of less than 1 degree indicates sufficient crystallinity (structure) of the material layer. The XRD rocking curve has been normalized to 1, and therefore the half maximum is about 0.5. The full width at half maximum for the first line 310 and the second line 312 is less than 1 degree, while the FWHM for the third line 314 is about 1 degree. The FWHM diagram for the first line 310, the second line 312, and the third line 314 shows that the crystallinity of the material layer is consistent and uniform from the center point (corresponding to the first line 310) to the outer edge of the substrate (corresponding to the third line 314). Therefore, the deposition process discussed above improves the bowing of the substrate having the material layer deposited on the substrate, while maintaining sufficient crystallinity and uniform crystal quality within the material layer.

[0060] Figure 4 4 is a graph 400 illustrating data showing substrate bowing after deposition of a material layer on the substrate according to some embodiments. The material layer is deposited on the substrate by a deposition process such as described above. Figure 1 , Figure 2A and Figure 2B The substrate bow depicted in graph 400 represents the bow of a substrate having 200 nm thick material deposited on the substrate. The vertical axis of graph 400 represents substrate bow and the horizontal axis is the position on the substrate from the center point of the substrate (Y=0 mm).

[0061] A first line 404 on the graph 400 depicts a bow of a substrate having a material layer deposited on the substrate. The pressure of the PVD process for depositing the material layer is approximately between about 2 mTorr and about 6 mTorr, such as 5.2 mTorr. The deposition process is repeated about eight times to achieve a material layer thickness of 200 nm. That is, the thickness of the material layer deposited by each of the eight operations is about 25 nm. No post-deposition processes, such as bombardment, are performed on the material layer. As depicted by the first line 404, the corresponding substrate has a total bow amplitude of about 10 microns from any outer edge (Y=±150 mm) to the center (Y=0 mm). The surface roughness of the material layer deposited on the substrate depicted by the first line 404 is about 1.24 nm.

[0062] A second line 402 on the graph 400 depicts a bowed curvature of a substrate having a material layer disposed on the substrate. The material layer is deposited on the substrate in intervals to achieve a thickness of about 200 nm. The deposition operation is repeated between about 6 and about 12 times, such as about 8 times. That is, the thickness of the material layer deposited on the substrate by each deposition operation is between about 16 nm and about 33 nm, such as about 25 nm.

[0063] After depositing each 20 nm material layer, perform the following steps such as those described above: Figure 1 As depicted by second line 402, the corresponding substrate has a total bowing amplitude of about 135 microns from any outer edge (Y=±150 mm) to the center (Y=0 mm). The surface roughness of the material layer deposited on the substrate depicted by second line 402 is about 0.86 nm. The pressure of the PVD process used to deposit the material layer is between about 2 mTorr and about 6 mTorr, such as 2.5 mTorr.

[0064] A third line 406 on the graph 400 depicts a bowed substrate having a material layer disposed on the substrate. The material layer is deposited on the substrate at intervals to achieve a thickness of about 200 nm. The deposition operation is repeated between about 6 and about 12 times, such as about 8 times. The pressure of the PVD process used to deposit the material layer is between about 2 mTorr and about 6 mTorr, such as 2.5 mTorr. After depositing the 200 nm material layer, a process such as described above is performed. Figure 1 The bombardment process discussed. As depicted by the third line 406, the corresponding substrate has a total bowing amplitude of about 13 microns from any outer edge (Y=±150 mm) to the center (Y=0 mm). The surface roughness of the material layer deposited on the substrate depicted by the third line 406 is about 0.97 nm.

[0065] As discussed above, the surface roughness of the material layer deposited on the substrate corresponding to the second line 402 and the third line 406 after the bombardment process is smoother than the material layer deposited on the substrate corresponding to the first line 404 without the bombardment process. Although the bombardment process performed on the substrate corresponding to the second line 402 provides a slightly smoother surface roughness than the substrate corresponding to the third line 406 on which the bombardment process is performed, the bow of the substrate corresponding to the third line 406 is significantly better than the bow of the substrate corresponding to the second line 402. That is, the bombardment operation after each deposition interval of the deposition interval of the material layer on the substrate corresponding to the second line 402 results in significantly increased substrate bow compared to the single bombardment operation after the deposition of the material layer corresponding to the third line 406. Therefore, both low substrate bow and smooth surface roughness are achieved using a single bombardment operation after the deposition of the material layer.

[0066] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope of the disclosure is determined by the claims which follow.

Claims

1. A method for depositing a composite nitride material on a substrate, the method comprising the following steps: depositing a layer of material on a substrate, the substrate having a known bowed curvature; and A bias voltage applied to the substrate is adjusted while depositing the material layer, the bias voltage minimizing bowing of the substrate, wherein the bias voltage is adjusted based on a thickness of the material layer deposited on the substrate and the known bowing of the substrate, and wherein the bias voltage is increased as the thickness of the deposited material layer increases. 2 . The method of claim 1 , wherein the pressure of the step of depositing the material layer is between 2 mTorr and 6 mTorr.

3. The method of claim 1, wherein the bias voltage applied to the substrate is between 40 Watts and 100 Watts. The method of claim 1 , wherein the thickness of the material layer is between 100 nanometers and 2500 nanometers. The method of claim 1 , wherein the power used to deposit the material layer is between 4 kW and 10 kW.

6. The method of claim 1, wherein the bias voltage applied to the substrate is between 40 Watts and 80 Watts, and wherein the bias voltage is used to reduce a bowed profile of the substrate.

7. The method of claim 1, wherein the step of adjusting the bias voltage comprises the following steps: applying a first bias voltage while depositing a first portion of the layer of material; and A second bias is applied while depositing a second portion of the material layer, wherein the first bias is different from the second bias. The method of claim 1 , wherein the material layer comprises aluminum nitride.

9. The method of claim 8, wherein the material layer further comprises scandium in a concentration between 1 atomic percent and 10 atomic percent.

10. The method of claim 8, wherein the material layer further comprises scandium in a concentration between 10 atomic percent and 25 atomic percent.

11. A method for depositing a complex nitride material on a substrate, the method sequentially comprising the following steps: depositing a layer of material on a substrate, the substrate having a known bow curvature; adjusting a bias voltage applied to the substrate while depositing the material layer on the substrate, the bias voltage minimizing bowing of the substrate such that a final substrate bowing in any direction is maintained to less than 100 microns, wherein the bias voltage is adjusted based on a thickness of the material layer deposited on the substrate and the known bowing of the substrate, and wherein the bias voltage is increased as the thickness of the deposited material layer increases; and An argon bombardment process is performed on the material layer. 12 . The method of claim 11 , wherein the pressure of the step of depositing the material layer is between 2 mTorr and 6 mTorr.

13. The method of claim 11, wherein the bias voltage applied to the substrate is between 40 Watts and 80 Watts.

14. A method for depositing a complex nitride material on a substrate, the method comprising the steps of: obtaining a measured substrate bow; depositing a layer of material on the substrate; and A bias voltage is applied while depositing the material layer, wherein the bias voltage is determined based on the measured substrate bow such that a final substrate bow in any direction is maintained to less than 100 microns.

15. The method of claim 14, further comprising performing an argon bombardment process on the material layer, wherein the argon bombardment process comprises: generating an argon plasma positioned on the surface of the substrate; and exposing the material layer to the argon plasma to reduce surface roughness of the material layer, and wherein a power of the argon bombardment process is between 250 W and 1000 W and a duration of the argon bombardment process is between 10 seconds and 400 seconds.

16. The method of claim 15, wherein the power used to deposit the material layer is between 4 kW and 10 kW.

17. The method of claim 14, wherein the thickness of the material layer is between 100 nanometers and 2500 nanometers. The method of claim 14 , wherein the material layer comprises aluminum nitride.

19. The method of claim 18, wherein the material layer further comprises scandium in a concentration between 1 atomic percent and 10 atomic percent.

20. The method of claim 18, wherein the material layer further comprises scandium in a concentration between 10 atomic percent and 25 atomic percent.

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