Method for depositing high quality pvd films

Abstract

Embodiments described herein include methods for depositing a material layer on a substrate while controlling bowing of the substrate and surface roughness of the material layer. A bias voltage applied to the substrate while depositing the material layer is adjusted to control bowing of the substrate. A bombardment process is performed on the material layer to improve surface roughness of the material layer. The bias voltage and the bombardment process improve uniformity of the material layer and reduce occurrences of material layer cracking caused by bowing of the substrate.

Description

[0001] background

[0002] field

[0003] Embodiments of this disclosure generally relate to methods for processing substrates, and more specifically, to methods for depositing films on substrates having reduced substrate bow and improved film quality. Background Technology

[0004] Physical vapor deposition (PVD) is frequently used to deposit aluminum nitride (AlN) films onto substrates. In some applications, high crystal quality is desired for the AlN film. To achieve high-quality films, the AlN film thickness is typically relatively large. For example, the thickness of AlN films is usually between approximately 300 nm and approximately 2 μm. However, using this thickness of film introduces other problems. For example, a thick AlN film causes the substrate to bend, leading to film breakage. The bending of the substrate can also affect subsequent substrate processing. For example, the bending of the substrate can result in uneven light distribution during photolithography processes.

[0005] Therefore, improved techniques are needed for depositing films. Summary of the Invention

[0006] In one embodiment, a method for depositing material on a substrate is provided. The method includes depositing a material layer on the substrate. The method further includes adjusting a bias voltage applied to the substrate while depositing the material layer, the bias voltage controlling the bow-shaped bending of the substrate. The method further includes performing a bombardment process on the material layer.

[0007] In another embodiment, a method for depositing material on a substrate is provided. The method sequentially includes adjusting a bias voltage applied to the substrate, the bias voltage being between about 30 W and about 80 W, while depositing a material layer on the substrate, and performing a bombardment process on the material layer.

[0008] In another embodiment, a method for processing a substrate is provided. The method includes depositing a material layer on the substrate disposed in a process chamber. The method further includes adjusting a bias voltage applied to the substrate during the deposition of the material layer. The method further includes generating argon plasma and bombarding the material layer with argon plasma. Attached Figure Description

[0009] The above-described features of this disclosure can be understood in detail by referring to the embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings are merely exemplary embodiments and should not be considered as limiting the scope of this disclosure, as other equally effective embodiments are permissible.

[0010] Figure 1 The operation of a method for depositing a film on a substrate is illustrated according to some embodiments.

[0011] Figure 2A It is a graph illustrating data on the bow-shaped bending of a substrate after a material layer is deposited on it, according to certain embodiments.

[0012] Figure 2B It is a graph illustrating data on the bow-shaped bending of a substrate after a material layer is deposited on it, according to certain embodiments.

[0013] Figure 3 It is a graph illustrating, according to certain embodiments, the quality data of a material layer after it has been deposited on a substrate.

[0014] Figure 4 It is a graph illustrating data on the bow-shaped bending of the substrate after deposition on the substrate, according to certain embodiments.

[0015] To facilitate understanding, the same reference numerals have been used as much as possible to represent common elements in the figures. It should be understood that elements and features of one embodiment may be beneficially incorporated into other embodiments without further explanation. Detailed Implementation

[0016] The embodiments described herein include a method for depositing a material layer on a substrate while controlling the bow-shaped bending of the substrate and the surface roughness of the material layer. The bias voltage applied to the substrate during material layer deposition is adjusted to control the bow-shaped bending 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 material layer cracking caused by the bow-shaped bending of the substrate.

[0017] In one embodiment, physical vapor deposition (PVD) can be used to deposit the material layer. During the deposition operation, a substrate is disposed on a substrate support base. In one embodiment, the substrate support base is an electrostatic chuck. A first electrode is disposed in the substrate support base and provides an adsorption force to the substrate. A second electrode is disposed in the base and provides a bias voltage to the substrate surface opposite to the base. The bias voltage applied to the substrate at least partially controls the bow-shaped bending of the substrate caused by the deposition operation.

[0018] Figure 1 The operation of a method 100 for depositing a film on a substrate is illustrated according to some embodiments. At operation 102, a physical vapor deposition (PVD) process is performed to deposit material on the substrate. The PVD process includes sputtering 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.

[0019] In some embodiments that can be combined with one or more of the embodiments discussed above, the material deposited on the substrate includes a scandium-containing material. In some embodiments that can be combined with one or more of the embodiments discussed above, the material layer includes scandium at a concentration between about 1 atomic percent and about 25 atomic percent. For example, the material layer may include 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.

[0020] The thickness of the material layer deposited on the substrate is between about 200 nanometers and about 2,500 nanometers, for example, about 1 micrometer. In some embodiments that can be combined with one or more of the embodiments described above, the PVD process is divided into more than one deposition operation. For example, the deposition operation can be repeated between about 4 and about 30 times, for example, between about 5 and about 10 times, such as about 8 times. That is, the material layer can be a stacked structure of multiple smaller layers that ultimately form the material layer.

[0021] The duration of a PVD process can depend on the number of deposition operations. For example, a material layer with a thickness of approximately 1.5 micrometers can be deposited in between approximately 20 and approximately 50 deposition operations, such as approximately 30 deposition operations. Each deposition operation can have a duration between approximately 30 and approximately 80 seconds, such as between approximately 45 and approximately 60 seconds, such as approximately 57 seconds. The power of a PVD process ranges from approximately 5 kW to approximately 8.5 kW, such as approximately 8 kW.

[0022] As another example, a material layer with a thickness of approximately 200 nanometers can be deposited in between approximately 5 and approximately 10 deposition operations, such as approximately 8 deposition operations. Each deposition operation can have a duration between approximately 10 seconds and approximately 60 seconds, for example, between approximately 15 seconds and approximately 30 seconds, such as approximately 25 seconds. Any particular deposition operation can have a longer or shorter duration than previous or subsequent deposition operations. The thickness of the material deposited during each deposition operation can be different. For example, five deposition operations can deposit 5 nm of material, while eight subsequent deposition operations can deposit 20 nm of material.

[0023] While depositing material on the substrate, the substrate may be bowed (e.g., curved). To reduce the amount of bowing, a bias voltage is applied to the substrate during the deposition process. The bias voltage can be applied to the substrate during each deposition operation. In one embodiment that can be combined with one or more of the embodiments discussed above, a single bias voltage (e.g., 50W) is applied to the substrate during each deposition operation. The same bias voltage (e.g., 50W) can be applied to the substrate during each deposition operation.

[0024] In some embodiments that can be combined with one or more of the embodiments described above, 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 approximately 40 W may be applied during the first 10 deposition operations, and a second bias of 60 W may be applied during the subsequent 12 deposition operations.

[0025] In some embodiments that can be combined with one or more of the embodiments described above, the bias voltage applied to the substrate can be determined based on the substrate bowing caused by a previous deposition operation. For example, a first bias voltage applied to the substrate during a first deposition operation can cause the substrate to bow. The bowing of the substrate is measured after the first deposition operation. The bias voltage applied to the substrate during subsequent deposition operations can be determined based on the measured substrate bowing, such that the bias voltage applied during the subsequent operation cancels out the measured substrate bowing. That is, after subsequent deposition operations, the substrate bowing is negligible.

[0026] For example, a bias voltage (e.g., 40W) for creating a concave substrate bow bend can be applied to the substrate after a deposition operation (e.g., 60W) for creating a convex substrate bow bend. That is, the bias voltage applied to the substrate can reduce the bow bend of the substrate by applying a bow bend opposite to that created by the previous deposition operation. The bias voltage applied to the substrate during the deposition operation can alternate between the bias voltage causing a convex substrate bow bend and the bias voltage causing a concave substrate bow bend. Therefore, the bow bend of the substrate having a material layer deposited on it is substantially reduced.

[0027] In some embodiments that can be combined with one or more of the embodiments described above, the bow-shaped bend of the substrate is known before the material layer is deposited on the substrate. In this case, the bias voltage to achieve a suitable bow-shaped bend of the substrate can be determined based on the pre-existing bow-shaped bend of the substrate. For example, the bias voltage that causes a convex bow-shaped bend of the substrate can be applied to a substrate with a concave bow-shaped bend, such that the bow-shaped bend obtained on the substrate after the material layer is deposited on the substrate is substantially neutralized.

[0028] In some embodiments that can be combined with one or more of the embodiments discussed above, the bias applied during each deposition operation may differ from the bias applied during previous deposition operations. For example, the bias during the first deposition operation may be approximately 0 W. The bias may be increased for each subsequent deposition operation, such that the bias during the final deposition operation is approximately 100 W.

[0029] In some embodiments that can be combined with one or more of the embodiments described above, the bias voltage can be adjusted based on the thickness of the material deposited on the substrate. For example, the bias voltage can be increased as the thickness of the deposited material increases. With increasing material thickness, a larger bias voltage can achieve a suitable substrate bow profile.

[0030] In some embodiments that can be combined with one or more of the embodiments described above, the bias can be adjusted for each deposition operation based on a linear function. In other embodiments that can be combined with one or more of the embodiments described above, the bias can be adjusted for each deposition operation based on a step function.

[0031] During operation 102, the average bias voltage applied to the substrate is between approximately 30 W and approximately 100 W, for example, between approximately 50 W and approximately 75 W. The bias voltage applied to the substrate can be a continuous bias voltage or a pulsed bias voltage. During substrate processing, the bias voltage applied to the substrate is automatically adjusted by a controller.

[0032] Advantageously, adjusting the bias voltage applied to the substrate controls the bow-shaped bend of the substrate. Adjusting the bias voltage changes the bow-shaped bend of the substrate from a tensile bow-shaped bend to a compressive bow-shaped bend. That is, a substantially neutral bow-shaped bend profile is achieved for the substrate having a material layer disposed on the substrate. By controlling the bow-shaped bend of the substrate, damage to the material layer (e.g., cracking) is reduced. The bow-shaped bend of the substrate can also affect subsequent processing of the substrate. For example, the bow-shaped bend of the substrate can lead to uneven light distribution during photolithography processes. Furthermore, adjusting or regulating the substrate bias voltage does not degrade the quality of the material layer (e.g., crystallinity).

[0033] The pressure used during the PVD process can range from approximately 1.5 mTorr to approximately 6.5 mTorr, for example, between approximately 2 mTorr and approximately 3.5 mTorr, such as approximately 2.5 mTorr. The pressure can be adjusted to improve the surface roughness of the material layer.

[0034] At operation 104, an argon bombardment process is performed on a material layer deposited on a substrate. The argon bombardment process includes generating argon plasma in a process chamber. The bombardment process is performed for between approximately 50 seconds and approximately 250 seconds, for example, between approximately 100 seconds and approximately 200 seconds, such as approximately 150 seconds.

[0035] Advantageously, the bombardment process further improves the surface roughness of the deposited material layer without affecting the substrate bowing or the crystallinity (i.e., quality) of the material layer. After the bombardment process, the surface roughness of the material layer is between about 1.10 nanometers and about 0.85 nanometers, for example, about 0.99 nanometers.

[0036] In one embodiment that can be combined with one or more of the embodiments described above, method 100 can be repeated. For example, operation 102 can be performed to deposit material on a substrate for about 10 seconds to 30 seconds, such as about 22 seconds to 28 seconds, or even about 25 seconds. Then, the bombardment process of operation 104 can be performed for about 15 seconds to 45 seconds, such as about 20 seconds to 40 seconds, or even about 30 seconds. In this embodiment, method 100 can be repeated about 5 times to about 10 times, such as about 8 times, so 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.

[0037] Figure 2A This is a graph 200 illustrating data on the bow-shaped bending of a substrate after a material layer has been deposited on it, according to certain embodiments. The material layer is deposited on the substrate by a deposition process, such as the deposition process described above. Figure 1 The deposition processes discussed are similar. Corresponding to... Figure 2A The deposition process has a power of approximately 8kW.

[0038] The thickness of the material layer deposited on the substrate, corresponding to the arcuate curve depicted in Figure 200, is approximately 500 nm. The vertical axis of Figure 200 corresponds to the arcuate curve of the substrate, and the horizontal axis represents the position on the substrate at a distance from the center point (Y = 0 mm). Regarding... Figure 2A No post-processing was performed on the material layer under discussion.

[0039] The first line 252 on Figure 200 depicts an arcuate bend in the substrate having a material layer deposited on it. No bias is applied to the substrate corresponding to the first line 252 during processing. As depicted by the first line 252, the substrate has a convex arcuate bend, wherein the outer portion of the substrate (near the outer edge at approximately Y = ±150 mm) arcuate towards the surface on which the material layer is deposited, and the central portion of the substrate (near the center of the substrate at approximately Y = 0 mm) arcuate away from the surface on which the material layer is deposited. As an example, the total arcuate bend of the substrate corresponding to the first line 252 is between approximately 120 micrometers and approximately 180 micrometers, such as approximately 140 micrometers.

[0040] The second line 254 on Figure 200 depicts an arcuate bend in the substrate with a material layer deposited on it. During processing, the bias voltage applied to the substrate corresponding to the second line 254 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.

[0041] As depicted by the second line 254, the corresponding substrate has a convex arcuate bend, wherein the outer portion of the substrate (approximately Y = ±150 mm) arcuately bends towards the material layer deposited on the substrate, and the central portion of the substrate (approximately Y = 0 mm) arcuately bends away from the material layer. The arcuate bend of the substrate corresponding to the second line 254 is less than the arcuate bend of the substrate corresponding to the first line 252. The total arcuate bend of the substrate corresponding to the second line 254 is between approximately 90 micrometers and approximately 120 micrometers, such as approximately 105 micrometers. That is, the arcuate bend of the substrate corresponding to the second line 254 is reduced by approximately 25 percent compared to the arcuate bend of the substrate corresponding to the first line 252.

[0042] The third line 256 on Figure 200 depicts an arcuate bend in the substrate with a material layer deposited on it. During processing, the bias voltage applied to the substrate corresponding to the third line 256 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.

[0043] As depicted by line 256, the corresponding substrate has a convex arcuate bend (arcuate bend away from the material layer) near the center of the substrate (Y = 0 mm), and a concave arcuate bend (arcuate bend towards the material layer) near the outer edge of the substrate (Y = ±150 mm). The arcuate bend of the substrate corresponding to line 256 is less than (i.e., reduced) the arcuate bend of the substrate corresponding to line 254. For example, the arcuate bend of the substrate corresponding to line 256 is between about 10 micrometers and about 50 micrometers, such as about 20 micrometers. That is, the arcuate bend of the substrate corresponding to line 256 is reduced by about 80% compared to the arcuate bend of the substrate corresponding to line 254.

[0044] The fourth line 258 on Figure 200 depicts an arcuate bend in the substrate with a material layer deposited on it. During processing, the bias voltage applied to the substrate corresponding to the fourth line 258 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 approximately 50W and approximately 80W, such as approximately 60W.

[0045] As depicted by line 258, the corresponding substrate has a concave arcuate bend, wherein the central portion of the substrate (near the center of the substrate at Y = 0 mm) arcuately towards the material layer, and the outer portion of the substrate (near the outer edge of the substrate at Y = ±150 mm) arcuately away from the material layer. The arcuate bend of the substrate corresponding to line 258 is greater than that of the substrate corresponding to line 256. However, the arcuate bend of the substrate corresponding to line 258 is smaller than that of the substrates corresponding to lines 252 and 254.

[0046] The bias applied to the substrate corresponding to line 258 results in an increase in the arcuate curvature of the substrate compared to that of the substrate corresponding to line 256. For example, the arcuate curvature of the substrate corresponding to line 258 is between approximately 50 micrometers and approximately 150 micrometers, such as approximately 75 micrometers. Therefore, the arcuate curvature of the substrate corresponding to line 258 is approximately 30 percent greater than that of the substrate corresponding to line 256. Line 260 in Figure 200 depicts the arcuate curvature of the substrate with a material layer deposited on it. During processing, the bias applied to the substrate corresponding to line 260 is higher than the bias applied to the substrate corresponding to line 258. For example, the bias applied to the substrate corresponding to line 260 is between approximately 65 W and approximately 120 W, such as approximately 100 W.

[0047] As depicted by line 260 (fifth line), the corresponding substrate has a concave arcuate bend, wherein the central portion of the substrate (near the center of the substrate at Y = 0 mm) arcuately towards the material layer, and the outer portion of the substrate (near the outer edge of the substrate at Y = ±150 mm) arcuately away from the material layer. The arcuate bend of the substrate corresponding to line 260 is greater than that of the substrates corresponding to lines 252 (first line), 254 (second line), 256 (third line), and 258 (fourth line). The maximum arcuate bend of the substrate corresponding to line 260 is approximately 375 micrometers.

[0048] Although the first line 252 and the second line 254 are illustrated as having a convex arcuate bend, these lines may have a concave arcuate bend depending on various parameters (such as the bias voltage applied to the substrate or on which surface of the substrate a material layer is deposited). Similarly, the arcuate bends of the substrate corresponding to the third line 256, the fourth line 258, and the fifth line 260 may be the opposite of those depicted in Figure 200 and described above.

[0049] As illustrated in Table 200, the bias voltage applied to the substrate during material layer deposition controls the substrate's bow-shaped curvature. For example, as the bias voltage increases, the bow-shaped curvature decreases until a certain point, after which it increases. Based on Table 200, the bias voltage that minimizes the substrate's bow-shaped curvature is applied to the substrate between approximately 40W and approximately 60W during material layer deposition. The bias voltage that minimizes the substrate's bow-shaped curvature can be varied 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 bias deposition operation, etc.

[0050] Figure 2B The diagram 250 illustrates data on minimum substrate bowing after a material layer of a specific thickness has been deposited on a substrate, according to certain embodiments. The diagram includes one or more lines 210-218, each corresponding to a substrate with a material layer of varying thickness deposited on it. As discussed below, the thickness of the material layer decreases from the first line 210 to the fifth line 218. The deposition process pressure for depositing the material layer is between approximately 4 mTorr and approximately 6 mTorr, such as approximately 5.2 mTorr. The vertical axis of diagram 250 corresponds to the substrate bowing in micrometers, and the horizontal axis corresponds to the position on the substrate from the outer edge (Y = ±150 mm) to the center point (Y = 0 mm). Regarding... Figure 2B No post-processing was performed on the material layer under discussion.

[0051] First line 210 depicts an arcuate bend in the substrate on which a material layer of approximately 2500 nm thickness is deposited. The bias voltage applied to the substrate during material layer deposition is between approximately 70 W and approximately 80 W, such as approximately 75 W. As depicted in first line 210, the substrate has a convex arcuate bend near its center (Y = 0 mm) and a concave arcuate bend near its edge at approximately Y = ±125 mm.

[0052] The second line 212 depicts the arcuate curvature of a substrate on which a material layer of approximately 1500 nm thickness is deposited. The bias voltage applied to the substrate during material layer deposition is between approximately 65 W and approximately 75 W, such as approximately 70 W. As depicted in the second line 212, the corresponding substrate has a convex arcuate curvature near the center (Y = 0 mm) and a concave arcuate curvature near the edge at approximately Y = ±125 mm. The arcuate curvature of the substrate corresponding to the second line 212 is reduced by approximately 50% compared to the substrate corresponding to the first line 210.

[0053] The third line 214 depicts the arcuate curvature of a substrate on which a material layer of approximately 1000 nm thickness is deposited. The bias voltage applied to the substrate during material layer deposition is between approximately 60 W and approximately 70 W, such as approximately 65 W. As depicted in the third line 214, the corresponding substrate has a convex arcuate curvature near the center (Y = 0 mm) and a concave arcuate curvature near the edge at approximately Y = ±125 mm. The arcuate curvature of the substrate corresponding to the third line 214 is reduced by approximately 25 percent compared to the substrate corresponding to the second line 212.

[0054] Line 216 depicts the arcuate curvature of a substrate on which a material layer of approximately 400 nm thickness is deposited. The bias voltage applied to the substrate during material layer deposition is between approximately 50 W and approximately 60 W, such as approximately 55 W. As depicted in line 216, the corresponding substrate has a convex arcuate curvature near the center (Y = 0 mm) and a concave arcuate curvature near the edge at approximately Y = ±125 mm. The arcuate curvature of the substrate corresponding to line 216 is reduced by approximately 50% compared to the substrate corresponding to line 214.

[0055] Line 218 depicts the arcuate curvature of a substrate on which a material layer of approximately 200 nm thickness is deposited. The average bias voltage applied to the substrate during material layer deposition is between approximately 45 W and approximately 55 W, such as approximately 50 W. As depicted in line 218, the corresponding substrate has a convex arcuate curvature near the center (Y = 0 mm) and a concave arcuate curvature near the edge at approximately Y = ±125 mm. The arcuate curvature of the substrate corresponding to line 218 is reduced by approximately 70% compared to the substrate corresponding to line 216.

[0056] The combination of material layer thickness and bias voltage discussed above demonstrates how the bias voltage applied to the substrate during material layer deposition can be used to adjust the substrate's bow-shaped curvature. For example, in... Figure 2B As illustrated in the diagram, the bias voltage applied to the substrate during the deposition of the material layer can influence or adjust the arcuate curvature of the substrate, depending on the thickness of the material layer deposited on the substrate. For a material layer with a thickness of less than 2500 nm, the arcuate curvature of the substrate in any direction can be maintained to less than about 100 micrometers.

[0057] Figure 3 This is a graph 300 illustrating, according to certain embodiments, data measuring the quality of a material layer after deposition on a substrate. The quality of the material layer is measured using X-ray diffraction rocking curve scanning along the AlN(002) crystal direction. The material layer is deposited on the substrate by a deposition process, such as those described above. Figure 1 , Figure 2A and Figure 2BThe deposition process discussed. The pressure used in the deposition process to deposit a 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 micrometers.

[0058] 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, approximately 70 mm from the center point, and near the edge, respectively. The full width at half maximum (FWHM) of the AlN(002) rocking curve, less than 1 degree, indicates sufficient crystallinity (structure) of the material layer. The XRD rocking curve has been normalized to 1, and therefore the FWHM is approximately 0.5. The FWHM for the first line 310 and the second line 312 is less than 1 degree, while the FWHM for the third line 314 is approximately 1 degree. The FWHM figures for the first line 310, the second line 312, and the third line 314 illustrate 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 bow-shaped curvature of the substrate with the material layer deposited on it, while maintaining sufficient crystallinity and uniform crystal quality within the material layer.

[0059] Figure 4 This is a graph 400 illustrating data on the bow-shaped bending of a substrate after a material layer has been deposited on it, according to certain embodiments. The material layer is deposited on the substrate by a deposition process, such as those described above. Figure 1 , Figure 2A and Figure 2B The deposition process is discussed. The substrate bow curve depicted in Figure 400 represents the bow curve of a substrate with a material thickness of 200 nm deposited on it. The vertical axis of Figure 400 represents the substrate bow curve, and the horizontal axis is the position on the substrate from the center point of the substrate (Y = 0 mm).

[0060] The first line 404 on Figure 400 depicts the bow-shaped bend of the substrate with a material layer deposited on it. The pressure of the PVD process for depositing the material layer is between approximately 2 mTorr and approximately 6 mTorr, such as 5.2 mTorr. The deposition process is repeated approximately eight times to achieve a material layer thickness of 200 nm. That is, the thickness of the material layer deposited through each of the eight operations is approximately 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-shaped bend amplitude of approximately 10 micrometers from either 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 approximately 1.24 nm.

[0061] The second line 402 on Figure 400 depicts an arcuate bend in the substrate with a material layer disposed on it. The material layer is deposited on the substrate in intervals to achieve a thickness of approximately 200 nm. The deposition operation is repeated between approximately 6 and approximately 12 times, such as approximately 8 times. That is, the thickness of the material layer deposited on the substrate by each deposition operation is between approximately 16 nm and approximately 33 nm, such as approximately 25 nm.

[0062] After depositing each 20nm material layer, procedures such as those mentioned above are performed. Figure 1 The discussion focuses on bombardment processes, such as the bombardment process. As depicted in line 402, the corresponding substrate has a total arc curvature of approximately 135 micrometers from any outer edge (Y = ±150 mm) to the center (Y = 0 mm). The surface roughness of the material layer deposited on the substrate, as depicted by line 402, is approximately 0.86 nm. The pressure used for the PVD process of depositing the material layer is between approximately 2 mTorr and approximately 6 mTorr, such as 2.5 mTorr.

[0063] Line 406 on Figure 400 depicts an arcuate bend in the substrate with a material layer disposed on it. The material layer is deposited on the substrate at intervals to achieve a thickness of approximately 200 nm. The deposition operation is repeated between approximately 6 and approximately 12 times, such as approximately 8 times. The pressure used for the PVD process to deposit the material layer is between approximately 2 mTorr and approximately 6 mTorr, such as 2.5 mTorr. After depositing the 200 nm material layer, procedures such as those described above are performed. Figure 1 The bombardment process discussed is a bombardment process. As depicted by the third line 406, the corresponding substrate has a total bow-shaped curvature of approximately 13 micrometers 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 approximately 0.97 nm.

[0064] As discussed above, the surface roughness of the material layers deposited on the substrates 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 compared to the substrate corresponding to the third line 406 where the bombardment process was performed, the bowing bend of the substrate corresponding to the third line 406 is significantly better than that of the substrate corresponding to the second line 402. That is, a bombardment operation after each deposition interval of the material layer on the substrate corresponding to the second line 402 results in a significantly increased substrate bowing bend compared to a single bombardment operation after the material layer deposition on the substrate corresponding to the third line 406. Therefore, a single bombardment operation after the material layer deposition is used to achieve both low substrate bowing bend and smooth surface roughness.

[0065] Although the foregoing describes embodiments of the present disclosure, other and further embodiments of the present disclosure may be conceived without departing from the basic scope of the present disclosure, and the scope of the present disclosure is defined by the appended claims.

Claims

1. A method for depositing a composite nitride material on a substrate, the method comprising the following steps: Depositing a material layer on a substrate; and While depositing the material layer, the bias voltage applied to the substrate is adjusted, the bias voltage controlling the bow-shaped bending of the substrate, wherein the bias voltage is adjusted based on the thickness of the material layer deposited on the substrate, the bias voltage is increased as the thickness of the deposited material layer increases, the step of depositing the material layer includes more than one deposition operation, and wherein the bias voltage is increased from the first deposition operation to the second deposition operation of the more than one deposition operation.

2. The method of claim 1, wherein the pressure during 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.

4. The method of claim 1, wherein the thickness of the material layer is between 100 nanometers and 2500 nanometers.

5. 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 applied to the substrate is between 40 watts and 80 watts, and wherein the bias is used to reduce the arcuate profile of the substrate.

7. The method of claim 1, wherein the step of adjusting the bias voltage comprises the following steps: A first bias voltage is applied while depositing the first portion of the material layer; and A second bias voltage is applied while depositing a second portion of the material layer on the first portion of the material layer, wherein the first bias voltage is less than the second bias voltage.

8. 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 at a concentration between 1 atomic percent and 10 atomic percent.

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

11. A method for depositing a composite nitride material on a substrate, the method sequentially comprising the following steps: While depositing a material layer on the substrate, a bias voltage applied to the substrate is adjusted, the bias voltage controlling the bow-shaped curvature of the substrate, wherein the bias voltage is adjusted based on the thickness of the material layer deposited on the substrate, and the bias voltage is increased as the thickness of the deposited material layer increases. The step of depositing the material layer includes more than one deposition operation, and wherein the bias voltage is increased from a first deposition operation to a second deposition operation of the more than one deposition operation; and An argon bombardment process is performed on the material layer.

12. The method of claim 11, wherein the pressure during 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 composite nitride material on a substrate, the method comprising the steps of: The first portion of the material layer deposited on the substrate; A first bias voltage is applied while the first portion of the material layer is deposited, the first bias voltage controlling the bow-shaped bending of the substrate; After the first portion of the material layer is deposited, the measured arcuate bending of the substrate is obtained; Deposit a second portion of the material layer on the first portion of the material layer; and A second bias voltage is applied simultaneously with the deposition of the second portion of the material layer, wherein the second bias voltage is determined based on the measured arcuate curvature of the substrate, such that the second bias voltage cancels out the measured arcuate curvature of the substrate.

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 a surface of the substrate; and exposing the material layer to the argon plasma to reduce the surface roughness of the material layer, and wherein the power of the argon bombardment process is between 250W and 1000W and the duration of the argon bombardment process is between 10 seconds and 400 seconds.

16. The method of claim 15, wherein the power used for depositing 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.

18. 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 at a concentration between 1 atomic percent and 10 atomic percent.

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

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