Quartz glass member for exposing film deposition gas and method for manufacturing the same

Abstract

To provide a quartz glass member for exposing film deposition gas, obtained by increasing a derivative surface area calculated from a BET specific surface area without having a dimension, shape and size larger than those of the conventional quartz glass member for exposing film deposition gas and without causing increase in labor or cost.SOLUTION: A quartz glass member for exposing film deposition gas includes: a tabular quartz glass member body; a plurality of linear protrusions formed in at least a part of the surface of the quartz glass member body and having a cross-sectional approximate square; and a plurality of micro cracks formed on at least one side surface of the linear protrusion. When setting a relationship between a dimension surface area calculated from a dimension, having the linear protrusions and set to 1 and the derivative surface area of the quartz glass member for exposing the film deposition gas, having the linear protrusions and the micro cracks, calculated from a BET specific surface area obtained by a BET measurement method to B times, B is 5 or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a quartz glass member for exposure to a film-forming process gas, which is placed in a reaction chamber together with a semiconductor substrate to be subjected to film-forming process during film-forming process of the semiconductor substrate, and has an increased exposure area to the film-forming process gas, and a method for manufacturing the same. [Background technology]

[0002] Conventionally, in the manufacturing process of semiconductor devices, various film formation processes, such as CVD (Chemical Vapor Deposition), are performed on semiconductor substrates such as silicon wafers. In such film formation processes, the semiconductor substrates are placed on a wafer holding jig called a wafer boat and carried into a reaction chamber, where the film formation process is performed.

[0003] In such a film formation process using a wafer holding jig, a wafer boat is made of quartz glass, a material that does not react with the processing gas, and semiconductor substrates are placed on the wafer boat.The semiconductor substrates are then placed in a reaction chamber together with other components made of quartz glass, a material that does not react with the processing gas, and the film formation process is performed.

[0004] The semiconductor substrates on which the film is formed have uneven surfaces due to the process, increasing their surface area compared to semiconductor substrates with flat surfaces. Therefore, in order to ensure uniform film formation on the semiconductor substrates, there was a need to increase the surface area as much as possible of the quartz glass members (sometimes called dummy wafers) exposed to the film formation process gas in the reaction chamber.

[0005] In the case of the gas distribution adjustment member described in Patent Document 1, the surface area was based on the outer diameter dimension, so the presence of tiny cracks (microcracks) was not taken into consideration, and there was a problem in that the actual surface area, including fine irregularities on the surface, could not be quantitatively evaluated.

[0006] The exposed area-increasing quartz glass member described in Patent Document 2 is a technology for controlling variations in the dimensions and shape of the groove depth, but does not control the size of the actual surface area that is thought to affect gas adsorption.

[0007] The manufacturing method of increasing the surface area by creating bubbles in silica glass as described in Patent Document 3 requires high-pressure, high-temperature treatment, which is troublesome and costly.

[0008] On the other hand, there are limitations on the shape and size of the quartz glass member used for film formation, and the dimensions and size cannot be increased without limit, so there is a limit to how much the surface area can be increased by tweaking the dimensions and size. Therefore, it has been necessary to clarify the factors that contribute to increasing the surface area of ​​the quartz glass member used for film formation without being affected by the size limitations, and to implement these factors on the quartz glass member.

[0009] Therefore, the inventors created quartz glass members with increased exposed area using different jigs in the processing step based on the conditions in Example 1 of Patent Document 2, and found that even with the same finished dimensions, the BET value (Brunaure Emmett Teller Value) differed depending on the grinding stone used, resulting in differences in quality during film formation. Furthermore, to clarify the cause of this difference, they conducted an investigation and found that even with the same finished dimensions, the BET specific surface area differed depending on the processing conditions, and that using a member with a larger BET specific surface area resulted in better quality during film formation. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Patent Publication No. 2015-173154 [Patent Document 2] WO2017 / 217309 [Patent Document 3] WO2022 / 215663 Summary of the Invention

Problems to be Solved by the Invention

[0011] An object of the present invention is to provide a quartz glass member for exposure to a film-forming treatment gas and a method for manufacturing the same, in which the derived surface area obtained from the BET specific surface area is increased without increasing the dimensional shape and size compared with a conventional quartz glass member for exposure to a film-forming treatment gas, and without causing an increase in labor and cost.

Means for Solving the Problems

[0012] The quartz glass member for exposure to a film-forming treatment gas of the present invention is a plate-shaped quartz glass member for exposure to a film-forming treatment gas used in a semiconductor film-forming process, and includes a plate-shaped quartz glass member body, a plurality of linear convex portions having a substantially square cross-section formed on at least a part of the surface of the quartz glass member body, and a plurality of microcracks formed on at least one side surface of the linear convex portions. The quartz glass member for exposure to a film-forming treatment gas has a relationship between the derived surface area obtained by the BET measurement method of the quartz glass member for exposure to a film-forming treatment gas having the linear convex portions and the microcracks and the dimensional surface area with the linear convex portions set to 1, and when this relationship is B times, B is 5 or more.

[0013] When the quartz glass member for exposure to a film-forming treatment gas is assumed to be a quartz glass member having only flat surfaces where the surface of the quartz glass member body has all flat surfaces without the linear convex portions and microcracks, and the dimensional surface area of only the flat surfaces obtained from the dimensions is set to 1, and when it is assumed to be a quartz glass member with linear convex portions having a surface where at least a part of the surface of the quartz glass member body has linear convex portions formed and no microcracks, and the relationship between the dimensional surface area with the linear convex portions obtained from the dimensions is A times, and the relationship between the derived surface area obtained from the BET specific surface area and the dimensional surface area of only the flat surfaces obtained from the dimensions set to 1 is C times, it is preferable to satisfy the relationship A < B < C.

[0014] It is preferable that the quartz glass member for exposure to a film-forming process gas satisfies the relationship that B is at least twice as large as A, and C is at least six times as large as A.

[0015] It is preferable that the microcracks formed within a unit length of 0.1 mm on at least one side of the linear convex portion have an average depth of 8 μm or more per microcrack and a total depth of all microcracks per unit length of 50 μm or more.

[0016] The microcracks are preferably enlarged microcracks that have been enlarged by etching.

[0017] It is preferable that the BET specific surface area obtained by BET measurement of the quartz glass member for exposure to a film-forming process gas, which contains the enlarged microcracks, is at least 7 times the BET specific surface area obtained by BET measurement of a quartz glass member whose surface is entirely flat, free from the linear convex portions and microcracks.

[0018] It is preferable that the BET specific surface area obtained by BET measurement of the quartz glass member for exposure to a film-forming process gas, which contains the enlarged microcracks, is 19 times or more larger than the BET specific surface area obtained by BET measurement of a quartz glass member having only flat surfaces, i.e., a quartz glass member whose surface is entirely flat and free of linear convexities and microcracks.

[0019] It is preferable that the thickness of the silica glass member body is 1 to 1.5 mm, and the height of the linear protrusions is 0.6 mm or more and less than 1.5 mm.

[0020] The method for manufacturing a quartz glass member for exposure to a film formation process gas of the present invention is a method for manufacturing a quartz glass member for exposure to a film formation process gas, which includes the steps of forming a linear convex portion with a roughly square cross section on at least a part of the quartz glass member body using a grinding blade, and forming a plurality of microcracks on at least one side of the linear convex portion, and in which the derived surface area calculated from the BET specific surface area of ​​the quartz glass member for exposure to a film formation process gas obtained by BET measurement is larger than the dimensional surface area calculated from the dimensions of the quartz glass member for exposure to a film formation process gas.

[0021] It is preferable to include a step of etching the quartz glass member body having the linear convex portions with microcracks formed therein to a depth of 0.1 μm to 0.6 μm, thereby enlarging the microcracks to form enlarged microcracks.

[0022] Preferably, the etching is performed by an HF cleaning step. [Effects of the Invention]

[0023] The present invention aims to provide a quartz glass member for exposure to a film-forming process gas, which has an increased derived surface area calculated from the BET specific surface area, without increasing the dimensions, shape, or size of conventional quartz glass members for exposure to a film-forming process gas, and a method for manufacturing the same, without increasing the effort or cost. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a schematic plan view showing one embodiment of a disc-shaped quartz glass member for exposure to a film-forming process gas according to the present invention. [Figure 2] An example of the formation of linear convex portions on a quartz glass member for exposure to a film forming process gas according to the present invention is shown, where (a) is an enlarged cross-sectional view showing the surface on which linear convex portions have been formed, and (b) is an enlarged cross-sectional view showing the surface before linear convex portions have been formed. [Figure 3]1A and 1B are diagrams showing schematic diagrams of microcracks in a quartz glass member for exposure to a film-forming process gas according to the present invention, where (a) is a schematic diagram of a normal microcrack, and (b) is a schematic diagram of an enlarged microcrack. [Figure 4] FIG. 2 is an explanatory diagram illustrating magnifications A, B, C, and X used in the present invention. [Figure 5] 1A and 1B are schematic plan views showing one embodiment of a rotary grinding blade, in which (a) is a perspective view and (b) is a front view. [Figure 6] FIG. 1 is an explanatory diagram showing the shape of a sample for BET measurement. [Figure 7] 1 shows the results of an SEM observation photograph of Example 1 having a "medium" amount of microcracks. [Figure 8] 1 shows the results of an SEM observation photograph of Example 2 having a "large" amount of microcracks. [Figure 9] 1 shows the results of an SEM observation photograph of Comparative Example 1 having a "small" amount of microcracks. [Figure 10] FIG. 10 is an explanatory diagram illustrating a magnification E. [Figure 11] 10 is a microscope photograph showing the back surface of Experimental Example 6. [Figure 12] 10 is a microscope photograph showing the back surface of Experimental Example 7. [Figure 13] 10 is a microscope photograph showing the back surface of Experimental Example 8. DETAILED DESCRIPTION OF THE INVENTION

[0025] The following describes embodiments of the present invention, but these embodiments are shown by way of example only, and it goes without saying that various modifications are possible without departing from the technical spirit of the present invention. In the drawings, the same members are designated by the same reference numerals.

[0026] 1 and 2, reference numeral 10 denotes a quartz glass member for exposure to a film formation process gas according to the present invention. The quartz glass member for exposure to a film formation process gas 10 is a quartz glass member for exposure to a film formation process gas that is placed in a reaction chamber together with a semiconductor substrate to be subjected to a film formation process during a film formation process for the semiconductor substrate, and is exposed to the film formation process gas. The quartz glass member for exposure to a film formation process gas has a plate-shaped (disk-shaped in the illustrated example) quartz glass member body 12 and a plurality of linear protrusions 14 with a substantially rectangular cross section formed on at least a part of the quartz glass member body 12, thereby increasing the area exposed to the film formation process gas.

[0027] FIG. 2(b) shows a plate-shaped (disk-shaped in the illustrated example) quartz glass member body 12 before the formation of the linear protrusions 14. As shown in FIG. 2(b), the plate-shaped (disk-shaped in the illustrated example) quartz glass member body 12 has flat surfaces on both the front surface 16 and the back surface 18 before the formation of the linear protrusions 14. When the linear protrusions are formed, recesses 20 are formed along with the linear protrusions 14, as shown in FIG. 2(a). The linear protrusions 14 are composed of the front surface 16 and side surfaces 22a, 22b. The recesses 20 are composed of side surfaces 22a, 22b and a bottom surface 24. The side surfaces 22a, 22b of the recesses 20 are also the side surfaces of the linear protrusions 14. Note that while the illustration shows an example of a disk-shaped quartz glass member body 12, other shapes besides the disk shape are also possible, such as a plate-shaped quartz glass member body having a rectangular or polygonal shape with rounded corners.

[0028] 1 and 2(a) show an example in which linear protrusions 14 are formed on one plane (front side) of the quartz glass member body 12, but in order to increase the specific surface area, linear protrusions 14 may also be formed on the opposite surface (back side) from the one plane, so that linear protrusions 14 are formed on both sides of the quartz glass member body 12. Note that linear protrusions 14 can be formed by groove cutting into the quartz glass member body 12.

[0029] <About Microcracks> The quartz glass member 10 for exposure to a film-forming process gas according to the present invention is characterized in that, as shown in FIG. 3(a), multiple microcracks 26 are formed on at least one of the side surfaces 22a, 22b of the linear protrusions 14 shown in FIG. 2(a). Microcracks 26 may also be formed on the bottom surface 24. Microcracks refer to tiny fissures or crevices formed on the surface of the quartz glass member body 12. FIG. 3(a) schematically shows the microcracks 26 by enlarging a portion of the linear protrusions 14. In the example shown in FIG. 3(a), the microcracks 26 are formed on the side surface 22a of the linear protrusions 14. Such microcracks are also formed when the linear protrusions 14 are formed. In particular, microcracks can be formed by forming the linear protrusions 14 by grooving.

[0030] In the present invention, it is preferable that the microcracks 26 formed within a unit length of 0.1 mm on at least one side of the linear convex portion 14 have an average depth of 8 μm or more per microcrack and a total depth of all microcracks per unit length of 50 μm or more.

[0031] The microcracks shown schematically in Figure 3(b) are enlarged microcracks 28 that have been enlarged by etching. In the present invention, it is preferable that the microcracks are enlarged microcracks 28 that have been enlarged by etching. Although it is possible to remove processing contamination from the outermost surface of a quartz glass member using pure water, this method is preferable because etching removes the outermost surface and opens up closed microcracks, increasing the specific surface area. Note that enlarged microcracks refer to microcracks whose crack portions have become larger due to etching.

[0032] For the quartz glass member 10 for film-forming treatment gas exposure of the present invention, when the linear convex portion-attached dimensional surface area (surface area based on the outer dimensions without considering the presence of microcracks etc.) calculated from the surface of the quartz glass member main body 12 and the dimensions of the linear convex portion 14 is taken as 1, the relationship between the derived surface area obtained from the BET specific surface area of the quartz glass member for film-forming treatment gas exposure having the linear convex portion 14 and the microcracks 26 formed, and the linear convex portion-attached dimensional surface area is set to B times, and B is 5 or more. An explanatory diagram showing the magnification is shown in FIG. 4.

[0033] As shown in FIG. 4, the surface area in terms of dimensions of the quartz glass member main body 12 with the linear convex portion formed is made A times that of the quartz glass member main body 12 without the linear convex portion formed. Techniques for increasing such a surface area in terms of dimensions are disclosed in Patent Document 1 and Patent Document 2.

[0034] And for the quartz glass member 10 for film-forming treatment gas exposure of the present invention, when the surface 16 of the quartz glass member main body 12 is assumed to be a quartz glass member having only flat surfaces (that is, a quartz glass member main body 12 without the linear convex portion formed) having all flat surfaces without the linear convex portion 14 and microcracks 26, when the dimensional surface area of only the flat surfaces obtained from the dimensions is taken as 1, the relationship between the dimensional surface area with the linear convex portion obtained from the dimensions of the quartz glass member with the linear convex portion having a surface with at least a part of the surface of the quartz glass member main body having the linear convex portion formed and no microcracks, and the dimensional surface area with the linear convex portion is set to A times, and when the dimensional surface area of only the flat surfaces obtained from the dimensions is taken as 1, the relationship between the derived surface area obtained from the BET specific surface area and the dimensional surface area with the linear convex portion is set to C times, it is preferable to satisfy the relationship A < B < C.

[0035] Furthermore, it is preferable that the quartz glass member 10 for film-forming treatment gas exposure satisfies the relationships that B is 2 times or more of A and C is 6 times or more of A.

[0036] In the present invention, the BET specific surface area of the quartz glass member 10 for film-forming treatment gas exposure including the enlarged microcracks is preferably 7 times or more, more preferably 19 times or more, the BET specific surface area obtained by the BET measurement method, when the surface of the quartz glass member body is assumed to be a quartz glass member having only flat surfaces without the linear protrusions and microcracks, all of which are flat surfaces. In the present invention, the ratio of the BET specific surface area of the quartz glass member 10 for film-forming treatment gas exposure obtained by the BET measurement method to the BET specific surface area obtained by the BET measurement method when the surface of the quartz glass member body is assumed to be a quartz glass member having only flat surfaces without the linear protrusions and microcracks is referred to as magnification X.

[0037] <Regarding the BET measurement method> In the present invention, in order to define the specific surface area by the BET measurement method (gas adsorption method), the surface area can also include, as part of the surface area, the surface where microcracks are formed and fine irregularities. The measurement of the BET specific surface area by the BET measurement method shall comply with JIS Z8830:2013. The measurement method of the adsorbed gas amount shall be the carrier gas method, and the analysis of the adsorption data can be measured by the multi-point method or the one-point method.

[0038] In the present invention, the thickness of the quartz glass member body 12 is preferably 1 to 1.5 mm, and the height of the convex part of the linear convex part is preferably 0.6 mm or more and less than 1.5 mm.

[0039] The manufacturing method of the present invention is a manufacturing method of the quartz glass member 10 for film-forming treatment gas exposure, including a step of forming a linear convex part 14 having a substantially square cross-section on at least a part of the quartz glass member body 12 with a grinding blade, and a step of forming a plurality of microcracks 26 on at least one side surface 22a, 22b of the linear convex part 14. The manufacturing method of the quartz glass member for film-forming treatment gas exposure is such that the derived surface area obtained from the BET specific surface area of the quartz glass member for film-forming treatment gas exposure obtained by the BET measurement method is larger than the dimensional surface area obtained from the dimensions of the quartz glass member for film-forming treatment gas exposure.

[0040] The grinding blade is preferably, for example, a rotary grinding blade. For example, a multi-peripheral blade as shown in Fig. 5 can be used as the rotary grinding blade. In Fig. 5, the multi-peripheral blade 30 has a single disk-shaped base metal portion 32, a diamond abrasive grain base portion 36 formed on the outer periphery 34 of the disk-shaped base metal portion 32, and a diamond abrasive grain blade portion 40 formed by a plurality of blades 38 protruding from the diamond abrasive grain base portion 36 and integrally provided. An insertion hole 42 is drilled in the center, through which a rotary shaft is inserted. There are no particular restrictions on the conditions for cutting grooves using a grinding blade, but it is preferable that the feed speed of the rotary grinding blade is 10 to 300 mm / min. and the rotation speed is 1500 to 4000 mm / min. The binder for the grinding blade used can be any known binder, and is not particularly limited. Examples include metal, resin, and electrodeposition, with metal being preferred.

[0041] The manufacturing method of the present invention preferably includes a step of etching the quartz glass member 10 for exposure to a film-forming process gas to a depth of 0.1 μm to 0.6 μm, and enlarging the microcracks 26 to form enlarged microcracks 28.

[0042] It is also preferable that the etching be carried out by an HF cleaning step. By carrying out the HF cleaning step, the surface area, including the open shape of microcracks that affect gas adsorption evaluated by BET measurement, can be controlled by the amount of HF cleaning. The amount of HF cleaning can be selected appropriately depending on the surface area of ​​the quartz glass member body on which the linear convex portions are formed, but 0.3 μm is preferable. In this way, the surface area of ​​the quartz member, which is a factor that affects film thickness control, can be controlled more precisely.

[0043] Furthermore, by performing the HF cleaning process, the shape resulting from microcracks created by groove cutting or the like in the quartz glass member body 12 can be controlled by adjusting the amount of HF cleaning. This does not require silica glass having a structure with many bubbles, as in Patent Document 3, and therefore does not require special equipment or processes to obtain the raw quartz glass. This makes it possible to control the surface area without increasing costs or effort, and to obtain a quartz jig with a large surface area. [Example]

[0044] The present invention will be explained in more detail below by way of examples, but it goes without saying that these examples are given for illustrative purposes and should not be construed as limiting.

[0045] Example 1 A plate-shaped quartz member with multiple linear convex portions (groove shapes) was produced by groove-cutting a transparent quartz glass plate using a rotary grinding blade as shown in Figure 5. A metal-bonded grinding wheel was used for the grinding blade. The conditions for groove-cutting were a low feed rate (100 mm / min.) and a high rotation rate (1500-1700 rpm). The thickness of the plate-shaped member was 1.5 mm, and the groove depth was 0.6 mm. After groove formation, the plate-shaped member was subjected to HF cleaning to remove processing contamination, and a quartz glass member for exposure to a film-forming process gas of the present invention was obtained. The HF cleaning amount was 0.6 μm.

[0046] A plate-shaped sample for measuring the specific surface area by the BET measurement method was cut out from the member after HF cleaning, and the BET specific surface area was measured. The size of the plate sample in this case was 40 mm × 8 mm × 1.5 mm, and the dimensional surface area, which was the surface area calculated from the dimensions of the linear convex portions of the sample (surface width of the convex portion: 0.4 mm, bottom width of the concave portion: 0.2 mm, side height: 0.6 mm), was designated as S1. The shape of the plate sample used for measuring the specific surface area is shown in Figures 6(a) and (b). The BET specific surface area was measured by the Kr-BET method using krypton gas using a BELSORP MAX measuring device manufactured by MicrotracBEL, and the specific surface area obtained at this time was expressed as H1 (m 2 / g). The surface area of ​​the sample was calculated by multiplying H1 by the sample weight, and this surface area was designated as the derived surface area HS1. A double-side polished reference sample was prepared, which had the same size as the sample cut out from the plate-like member, no grooves, and all flat surfaces, and the BET specific surface area was measured in the same manner. The specific surface area of ​​the double-side polished sample obtained for reference was defined as H0 (m 2 / g) and the value of H1 / H0 was calculated, the magnification X was 7 times. The surface area calculated from the dimensions of a double-side polished sample with all flat surfaces was set to S0, and the relationship between the dimensions and the surface area S1, S1 / S0, was calculated, and the ratio A was 1.8. Furthermore, when the relationship between S1 and HS1, HS1 / S1, was calculated, the ratio B was found to be 6. Furthermore, when the relationship between S0 and HS1, HS1 / S0, was calculated, the ratio C was found to be 11. The results are shown in Table 1.

[0047] The cross section of the sample was observed by SEM to check the state of microcracks per 0.1 mm length formed on the side of the groove, and the number and depth of the microcracks were measured. The SEM observation photograph of Example 1 is shown in Figure 7, and the measurement results of the microcracks are shown in Table 2. The evaluation criteria for microcracks were as follows: Large: When the total depth per unit length (0.1 mm) is 100 μm or more Medium: When the total depth per unit length (0.1 mm) is 50 μm or more but less than 100 μm Small: When the total depth per unit length (0.1 mm) is less than 50 μm

[0048] As shown in Figure 7, it was confirmed that the sample of Example 1 had a "medium" amount of microcracks. As a result of measuring the microcracks from the SEM image shown in Figure 7, the total depth of the microcracks per 0.1 mm length was 65 µm, and the average depth was 8 µm per piece.

[0049] Furthermore, using the obtained quartz glass member for exposure to a film-forming process gas, semiconductor film formation was carried out by the following method, and the quality of the film formation was evaluated. The results are shown in Table 1. <Semiconductor film formation method and quality evaluation> The exposure quartz glass described in Example 1 was prepared, and a nitride film deposition test was conducted to verify the adsorption effect of the process gas onto the quartz glass member. The exposure quartz glass and the semiconductor substrate to be processed were placed in a reaction vessel where the film deposition process was performed, and the film deposition test was conducted. The film quality was evaluated by the ratio of the maximum film thickness (Max.) within the semiconductor substrate to the film thickness at the center of the semiconductor substrate after film deposition, which was set to 1. The evaluation criteria are as follows: Evaluation criteria ◎: Film thickness ratio less than 1.05 ○: Film thickness ratio 1.05 or more and less than 1.10 △: Film thickness ratio 1.10 or more and less than 1.30 ×: Film thickness ratio 1.30 or more

[0050] [Table 1]

[0051] [Table 2]

[0052] Example 2 A sample was prepared from a plate-shaped quartz member having a plurality of grooves fabricated under the same conditions as in Example 1, except that the HF cleaning amount was changed to 0.3 μm. Plate-shaped samples for BET measurement were cut out from the member after HF cleaning, and BET specific surface area measurement, microcrack observation, and film quality evaluation were carried out in the same manner as in Example 1. The size of the plate-shaped sample at this time was 40 mm x 8 mm x 1.5 mm, and the surface area calculated from these dimensions was defined as S2. The BET specific surface area was measured by the Kr-BET method using krypton gas, and the specific surface area obtained was calculated using H2(m 2 / g). The surface area of ​​the sample was calculated by multiplying H2 by the sample weight, and this surface area was taken as the derived surface area HS2. As in Example 1, a double-side polished reference sample was prepared that had the same size as the sample cut out from the plate-like member, had no grooves, and had all flat surfaces, and the BET specific surface area was measured in the same manner. The specific surface area of ​​the double-side polished sample obtained for reference was defined as H0 (m 2 / g) and the value of H2 / H0 was calculated, the magnification X was 9 times. As in Example 1, the surface area calculated from the dimensions of a double-side polished sample having all flat surfaces was set to S0, and the relationship between the size and surface area S2, S2 / S0, was calculated, and the ratio A was found to be 1.8. Furthermore, when the relationship between S2 and HS2, HS2 / S2, was calculated, the ratio B was 8. Furthermore, when the relationship between S0 and HS2, HS2 / S0, was calculated, the ratio C was 15. The results are shown in Table 1. Cross-sectional SEM observation of the sample was performed to examine the state of microcracks per 0.1 mm length formed on the groove side surface, and it was confirmed that there were "large" microcracks. Figure 8 shows an SEM observation photograph of Example 2. Measurement of the microcracks from the SEM observation image shown in Figure 8 revealed that the total depth of microcracks per 0.1 mm length was 222 μm, with an average depth of 25 μm per groove. The results are shown in Table 2.

[0053] Example 3 A sample was prepared from a plate-shaped quartz member having a plurality of grooves fabricated under the same conditions as in Example 1, except that the HF cleaning amount was changed to 0.15 μm. Plate-shaped samples for BET measurement were cut out from the member after HF cleaning, and BET specific surface area measurement, microcrack observation, and film formation quality evaluation were carried out in the same manner as in Example 1. The size of the plate-like sample at this time was 40 mm x 8 mm x 1.5 mm, and the surface area calculated from these dimensions was designated as S3. The BET specific surface area was measured by the Kr-BET method using krypton gas, and the specific surface area obtained was expressed as H3(m 2 / g). The surface area of ​​the sample was calculated by multiplying H3 by the sample weight, and this surface area was taken as the derived surface area HS3. As in Example 1, a double-side polished reference sample was prepared, which had the same size as the sample cut out from the plate-like member, no grooves, and all flat surfaces, and the BET specific surface area was measured in the same manner. The specific surface area of ​​the double-side polished reference sample obtained at this time was expressed as H0 (m 2 / g) and the value of H3 / H0 was calculated, the magnification X was 10 times. As in Example 1, the surface area calculated from the dimensions of a double-sided polished sample having all flat surfaces was set to S0, and the relationship between the dimension and surface area S3, S3 / S0, was calculated, and the ratio A was 1.8. Furthermore, when the relationship between S3 and HS3, HS3 / S3, was calculated, the ratio B was 10. Furthermore, when the relationship between S0 and HS3, HS3 / S0, was calculated, the ratio C was 17. The cross-section of the sample was observed with an SEM to check the state of microcracks per 0.1 mm in length formed on the side of the groove. It was confirmed that there were approximately "large" microcracks, similar to the SEM observation image of Example 2 shown in Figure 8.

[0054] Example 4 As in Example 1, a plate-shaped quartz member with multiple grooves was produced by groove-cutting a transparent quartz glass plate using a rotary grinding blade. A metal-bonded grinding wheel was used as the grinding blade. The groove-cutting conditions were the same as in Example 1, with grooves being cut on one flat surface (front surface) of the transparent quartz glass plate and then on the opposite surface (back surface) to form grooves on both surfaces. The thickness of the plate-shaped member was 1.5 mm, and the groove depth on both surfaces was 0.6 mm. After groove formation, the plate-shaped member was subjected to HF cleaning to remove processing contamination, with the HF cleaning amount being 0.3 μm. A plate-shaped sample for BET measurement was cut out from the member after HF cleaning, and similarly to Example 1, BET specific surface area measurement, microcrack observation, and film formation quality evaluation were carried out. The size of the plate-like sample at this time was 40 mm x 8 mm x 1.5 mm, and the surface area calculated from these dimensions was designated as S4. The BET specific surface area was measured by the Kr-BET method using krypton gas, and the specific surface area obtained was expressed as H4 (m 2 / g). The surface area of ​​the sample was calculated by multiplying H4 by the sample weight, and this surface area was taken as the derived surface area HS4. As in Example 1, a double-side polished reference sample was prepared that had the same size as the sample cut out from the plate-like member, had no grooves, and had all flat surfaces, and the BET specific surface area was measured in the same manner. The specific surface area of ​​the double-side polished sample obtained for reference was defined as H0 (m 2 / g) and the value of H4 / H0 was calculated, and the magnification X was 18 times. As in Example 1, the surface area calculated from the dimensions of a double-sided polished sample having all flat surfaces was set to S0, and the relationship between the dimension and surface area S4, S4 / S0, was calculated, and the ratio A was found to be 2.6. Furthermore, when the relationship between the aforementioned S4 and HS4, HS4 / S4, was calculated, the ratio B was found to be 9. Furthermore, when the relationship between S0 and HS4, HS4 / S0, was calculated, the ratio C was found to be 23. The cross-section of the sample was observed with an SEM to check the state of microcracks per 0.1 mm in length formed on the side of the groove. It was confirmed that there were approximately "large" microcracks, similar to the SEM observation image of Example 2 shown in Figure 8.

[0055] Example 5 In the same manner as in Example 1, grooves were cut into a transparent quartz glass plate using a rotary grinding blade to produce a plate-shaped quartz member with multiple grooves. A metal-bonded grinding wheel was used as the grinding blade. The conditions for cutting the grooves were a low feed rate and a high rotation rate for the rotary grinding blade. The thickness of the plate-shaped member was 1.5 mm, and the groove depth was 1 mm. After the grooves were formed, the plate-shaped member was subjected to HF cleaning to remove processing contamination, with the HF cleaning amount being 0.3 μm. A plate-shaped sample for BET measurement was cut out from the member after HF cleaning, and similarly to Example 1, BET specific surface area measurement, microcrack observation, and film formation quality evaluation were carried out. The size of the plate-like sample at this time was 40 mm x 8 mm x 1.5 mm, and the surface area calculated from these dimensions was designated as S5. The BET specific surface area was measured by the Kr-BET method using krypton gas, and the specific surface area obtained was expressed as H5(m 2 / g). The surface area of ​​the sample was calculated by multiplying H5 by the sample weight, and this surface area was taken as the derived surface area HS5. As in Example 1, a double-side polished reference sample was prepared that had the same size as the sample cut out from the plate-like member, had no grooves, and had all flat surfaces, and the BET specific surface area was measured in the same manner. The specific surface area of ​​the double-side polished sample obtained for reference was defined as H0 (m 2 / g) and the value of H5 / H0 was calculated, the magnification X was 19 times. As in Example 1, the surface area calculated from the dimensions of a double-side polished sample having all flat surfaces was set to S0, and the relationship between the dimensions and the surface area S5 was calculated, S5 / S0, and the ratio A was found to be 2.2. Furthermore, when the relationship between the aforementioned S5 and HS5, HS5 / S5, was calculated, the ratio B was found to be 13. Furthermore, when the relationship between S0 and HS5, HS5 / S0, was calculated, the ratio C was found to be 28. The cross-section of the sample was observed with an SEM to check the state of microcracks per 0.1 mm in length formed on the side of the groove. It was confirmed that there were approximately "large" microcracks, similar to the SEM observation image of Example 2 shown in Figure 8.

[0056] Example 6 In the same manner as in Example 1, grooves were cut into a transparent quartz glass plate using a rotary grinding blade to produce a plate-shaped quartz member with multiple grooves. The grinding blade used was the same metal-bonded grinding wheel as in Example 1. The conditions for cutting the grooves were a low feed speed and a high rotation speed for the rotary grinding blade. The thickness of the plate-shaped member was 1.5 mm, and the groove depth was 0.6 mm. To remove processing contamination from the plate-shaped member after groove formation, HF cleaning was not performed but pure water cleaning was performed. Plate-shaped samples for BET measurement were cut out from the member after pure water cleaning, and BET specific surface area measurement, microcrack observation, and film quality evaluation were performed in the same manner as in Example 1. The size of the plate-like sample at this time was 40 mm x 8 mm x 1.5 mm, and the surface area calculated from these dimensions was designated as S6. The BET specific surface area was measured by the Kr-BET method using krypton gas, and the specific surface area obtained was expressed as H6(m 2 / g). The surface area of ​​the sample was calculated by multiplying H6 by the sample weight, and this surface area was designated as the derived surface area HS6. As in Example 1, a double-side polished reference sample was prepared that had the same size as the sample cut out from the plate-like member, had no grooves, and had all flat surfaces, and the BET specific surface area was measured in the same manner. The specific surface area of ​​the double-side polished sample obtained for reference was defined as H0 (m 2 / g) and the value of H6 / H0 was calculated, the magnification X was 21 times. As in Example 1, the surface area calculated from the dimensions of a double-sided polished sample having all flat surfaces was set to S0, and the relationship between the dimension and surface area S6, S6 / S0, was calculated, and the ratio A was 1.8. Furthermore, when the relationship between the aforementioned S6 and HS6, HS6 / S6, was calculated, the ratio B was found to be 20. Furthermore, when the relationship between S0 and HS6, HS6 / S0, was calculated, the ratio C was found to be 36. The cross-section of the sample was observed with an SEM to check the state of microcracks per 0.1 mm in length formed on the side of the groove. It was confirmed that there were approximately "large" microcracks, similar to the SEM observation image of Example 2 shown in Figure 8.

[0057] Example 7 In the same manner as in Example 1, grooves were cut into a transparent quartz glass plate using a rotary grinding blade to produce a plate-shaped quartz member having multiple grooves. The grinding blade used was the same metal-bonded grinding wheel as in Example 1. The conditions for cutting the grooves were a low feed rate and a high rotation rate for the rotary grinding blade. The thickness of the plate-shaped member was 1.5 mm, and the groove depth was 0.6 mm. After the grooves were formed, the plate-shaped member was subjected to HF cleaning to remove processing contamination, with the HF cleaning amount being 0.7 μm. A plate-shaped sample for BET measurement was cut out from the member after washing with pure water, and similarly to Example 1, BET specific surface area measurement, microcrack observation, and film formation quality evaluation were carried out. The size of the plate-like sample at this time was 40 mm x 8 mm x 1.5 mm, and the surface area calculated from these dimensions was designated as S7. The BET specific surface area was measured by the Kr-BET method using krypton gas, and the specific surface area obtained was expressed as H7(m 2 / g). The surface area of ​​the sample was calculated by multiplying H7 by the sample weight, and this surface area was designated as the derived surface area HS7. As in Example 1, a double-side polished reference sample was prepared that had the same size as the sample cut out from the plate-like member, had no grooves, and had all flat surfaces, and the BET specific surface area was measured in the same manner. The specific surface area of ​​the double-side polished sample obtained for reference was defined as H0 (m 2 / g) and the value of H7 / H0 was calculated, and the magnification X was 6 times. As in Example 1, the surface area calculated from the dimensions of a double-sided polished sample having all flat surfaces was set to S0, and the relationship between the dimension and surface area S7, S7 / S0, was calculated, and the ratio A was 1.8. Furthermore, when the relationship between the aforementioned S7 and HS7, HS7 / S7, was calculated, the ratio B was found to be 5. Furthermore, when the relationship between S0 and HS7, HS7 / S0, was calculated, the ratio C was found to be 9. The cross-section of the sample was observed with an SEM to examine the state of microcracks per 0.1 mm in length formed on the side of the groove. It was confirmed that there were a "medium" amount of microcracks, similar to the SEM observation image of Example 1 shown in Figure 7.

[0058] Example 8 In the same manner as in Example 1, grooves were cut into a transparent quartz glass plate using a rotary grinding blade to produce a plate-shaped quartz member with multiple grooves. The grinding blade used was the same metal-bonded grinding wheel as in Example 1. The conditions for cutting the grooves were a low feed speed and a high rotation speed for the rotary grinding blade. The thickness of the plate-shaped member was 1.5 mm, and the groove depth was 0.6 mm. After the grooves were formed, the plate-shaped member was subjected to HF cleaning to remove processing contamination, and the HF cleaning depth was set to 0.9 μm. A plate-shaped sample for BET measurement was cut out from the member after washing with pure water, and BET specific surface area measurement, microcrack observation, and film formation quality evaluation were carried out in the same manner as in Example 1. The size of the plate-shaped sample in this case was 40 mm × 8 mm × 1.5 mm, and the surface area calculated from these dimensions was designated as S8. The BET specific surface area was measured by the Kr-BET method using krypton gas, and the specific surface area obtained was expressed as H8(m 2 / g). The surface area of ​​the sample was calculated by multiplying H8 by the sample weight, and this surface area was taken as the derived surface area HS8. As in Example 1, a double-side polished reference sample was prepared that had the same size as the sample cut out from the plate-like member, had no grooves, and had all flat surfaces, and the BET specific surface area was measured in the same manner. The specific surface area of ​​the double-side polished sample obtained for reference was defined as H0 (m 2 / g) and the value of H8 / H0 was calculated, and the magnification X was 6 times. As in Example 1, the surface area calculated from the dimensions of a double-sided polished sample having all flat surfaces was set to S0, and the relationship between the dimension and surface area S8, S8 / S0, was calculated, and the ratio A was found to be 1.8. Furthermore, when the relationship between the aforementioned S8 and HS8, HS8 / S8, was calculated, the ratio B was found to be 5. Furthermore, when the relationship between S0 and HS8, HS8 / S0, was calculated, the ratio C was found to be 8. When the cross section of the sample was observed with an SEM to check the state of microcracks, a "medium" amount of microcracks was confirmed, similar to the SEM observation image of Example 1 shown in FIG.

[0059] (Comparative Example 1) As in Example 1, a plate-shaped quartz member with multiple grooves was produced by cutting grooves into a transparent quartz glass plate using a rotary grinding blade. A resin-bonded grinding wheel was used for the grinding blade. The thickness of the plate-shaped member was 1.5 mm, and the groove depth was 0.6 mm. The conditions for cutting the grooves were a low feed speed and a high rotation speed of the rotary grinding blade. After the grooves were formed, the plate-shaped member was subjected to HF cleaning to remove processing contamination, and the HF cleaning depth was set to 0.3 μm. A plate-shaped sample for BET measurement was cut out from the member after HF cleaning, and similarly to Example 1, BET specific surface area measurement, microcrack observation, and film formation quality evaluation were carried out. The size of the plate-like sample at this time was 40 mm x 8 mm x 1.5 mm, and the surface area calculated from these dimensions was designated as S9. The BET specific surface area was measured by the Kr-BET method using krypton gas using a BELSORP MAX measuring device manufactured by MicrotracBEL, and the specific surface area obtained at this time was expressed as H9 (m 2 / g). The surface area of ​​the sample was calculated by multiplying H9 by the sample weight, and this surface area was taken as the derived surface area HS9. As in Example 1, a double-side polished reference sample was prepared that had the same size as the sample cut out from the plate-like member, had no grooves, and had all flat surfaces, and the BET specific surface area was measured in the same manner. The specific surface area of ​​the double-side polished sample obtained for reference was defined as H0 (m 2 / g) and the value of H9 / H0 was calculated, which was a factor of 3. As in Example 1, the surface area calculated from the dimensions of a double-side polished sample having all flat surfaces was taken as S0, and the relationship S9 / S0 was calculated, and the value A was found to be 1.3. Furthermore, when the relationship between S9 and HS9, HS9 / S9, was calculated, the value B was found to be 3. Furthermore, when the relationship between S0 and HS9, HS9 / S0, was calculated, the value C was found to be 4. Cross-sectional SEM observation of the sample was performed to check the state of microcracks, and it was confirmed that there were "small" microcracks. Figure 9 shows an SEM photograph of Comparative Example 1. Measurement of the microcracks from the SEM image shown in Figure 9 revealed that the total depth of microcracks per 0.1 mm length was 26 μm, with an average depth of 7 μm per piece. The results are shown in Table 2.

[0060] (Comparative Example 2) As in Example 1, a plate-shaped quartz member having multiple grooves was produced by groove-cutting transparent quartz glass using a rotary grinding blade. A metal-bonded grinding wheel was used for the grinding blade. The conditions for groove-cutting were a low feed rate and a high rotation rate for the rotary grinding blade. The thickness of the plate-shaped member was 1.5 mm, and the groove depth was 0.6 mm. After groove formation, the plate-shaped member was subjected to HF cleaning to remove processing contamination, with the HF cleaning amount being 5 μm. A plate-shaped sample for BET measurement was cut out from the member after HF cleaning, and BET specific surface area measurement, microcrack observation, and film formation quality evaluation were carried out in the same manner as in Example 1. The size of the plate-shaped sample in this case was 40 mm × 8 mm × 1.5 mm, and the surface area calculated from these dimensions was designated as S10. The BET specific surface area was measured by the Kr-BET method using krypton gas, and the specific surface area obtained was expressed as H10(m 2 / g). The surface area of ​​the sample was calculated by multiplying H10 by the sample weight, and this surface area was taken as the derived surface area HS10. As in Example 1, a double-side polished reference sample was prepared that had the same size as the sample cut out from the plate-like member, had no grooves, and had all flat surfaces, and the BET specific surface area was measured in the same manner. The specific surface area of ​​the double-side polished sample obtained for reference was defined as H0 (m 2 / g) and the value of H10 / H0 was calculated, which was found to be a factor of 1.8. As in Example 1, the surface area calculated from the dimensions of the double-side polished sample was taken as S0, and the relationship S10 / S0 was calculated, and the value A was found to be 1.8. Furthermore, when the relationship between S10 and HS10, HS10 / S10, was calculated, the value B was found to be 1. Furthermore, when the relationship between S0 and HS10, HS10 / S0, ​​was calculated, the value C was found to be 2. The cross section of the sample was observed using an SEM to check for microcracks per 0.1 mm in length formed on the side of the groove, but no microcracks were found.

[0061] From the above results, it was confirmed that the quartz glass member for exposure to a film-forming process gas according to the present invention has the above-mentioned B value of 5 or more, and that the derived surface area calculated from the BET specific surface area obtained by the BET measurement method is increased. Furthermore, as shown in Table 1, it was suggested that the film-forming quality is good when the etching amount is 0.6 μm or less, and that the film-forming quality deteriorates when the etching amount exceeds 0.6 μm.

[0062] <About the etching process> Table 3 also shows the difference in BET value due to the difference in the amount of etching (amount of HF washing) for the same BET measurement sample as used in Example 1.

[0063] [Table 3]

[0064] HF cleaning is necessary to remove contamination from the outer surface of the quartz jig to a depth of 0.1 μm or more. From the results in Table 3, the BET specific surface area of ​​the BET measurement sample does not change when the HF cleaning amount is 0.6 μm or more, and it is thought that the film quality deteriorates when it exceeds 0.6 μm. Therefore, it is thought that the etching amount by HF cleaning, i.e., the HF cleaning amount, is preferably 0.1 μm to 0.6 μm.

[0065] (Experimental Examples 1 to 5) Processing conditions The processing conditions for grooving a plate-shaped quartz glass member body are shown in Table 4. A plate-shaped quartz member having multiple groove shapes was produced in the same manner as in Example 1, except that the processing conditions for grooving were changed to those shown in Table 4. Then, a plate-shaped sample was cut out in the same manner as in Example 1, and BET specific surface area measurement and film formation quality evaluation were carried out. In Table 4, the differences in the groove cutting conditions are as follows: High rotation speed: 1500~4000rpm Low rotation speed: 500~1500rpm High feed rate: 300~600mm / min. Low feed rate: 10~300mm / min. The feed speed mentioned here refers to the speed at which the rotary grinding blade moves in a direction parallel to the plane of the plate-shaped quartz member that is the workpiece. The deterioration of the grinding blade was evaluated visually. In Table 4, the evaluation criteria for the quality during film formation are the same as those in Table 1, and the evaluation of the BET specific surface area is as follows: BET specific surface area large: 0.020m 2 / g or more, medium: 0.005m 2 / g or more 0.020m 2 / g or less, small: 0.005m 2 / g or less.

[0066] [Table 4]

[0067] Table 4 shows that metal is more suitable than resin for the binder of the grinding blade, and that a high rotation speed is more suitable than a low speed.

[0068] <Effects of sandblasting and grinding treatments> When a quartz glass member is subjected to sandblasting or grinding, fine cracks are generated. These fine cracks are also called microcracks, and the measurement results of the BET specific surface area when such sandblasting or grinding is performed are shown below as further experimental examples.

[0069] (Experimental Examples 6 to 8) Microcrack generation on sandblasted surface A plate-shaped sample was prepared with a groove cut on one surface of the front side in the same manner as in Example 2. The back side of the plate-shaped sample was subjected to sandblasting (Experimental Example 6: normal back side sandblasting, Experimental Example 7: strong back side sandblasting) or backside grinding (Experimental Example 8: high backside grinding roughness) under the conditions shown in Table 5. The cross sections of the sandblasted and ground surfaces were magnified and observed using a Keyence VHX-7000 microscope. The number and depth of microcracks generated per 0.1 mm were measured using the multipoint measurement function of the same device. The results are shown in Table 5. An explanatory diagram of the magnification E (effect of the back surface) in Table 5 is shown in Figure 10. Furthermore, a microscopic photograph of a cross section of the back surface of the sample after treatment obtained in Experimental Example 6 is shown in Figure 11, a microscopic photograph of a cross section of the back surface of the sample after treatment obtained in Experimental Example 7 is shown in Figure 12, and a microscopic photograph of a cross section of the back surface of the sample after treatment obtained in Experimental Example 8 is shown in Figure 13.

[0070] [Table 5]

[0071] From the above, it can be seen that the total depth of microcracks per unit length generated on the sandblasted surface is significantly smaller than that on the ground surface. Furthermore, the magnification E of the sandblasted surface in Table 5 is 1.2, which is not the same as that of the quartz glass member for exposure to film-forming process gases of the present invention. [Explanation of symbols]

[0072] 10: Quartz glass member for exposure to film forming process gas, 12: Quartz glass member body, 14: Linear convex portion, 16: Surface, 18: Back surface, 20: Concave portion, 22a, 22b: Side surface, 24: Bottom surface, 26: Microcrack, 28: Enlarged microcrack, 30: Multi-periphery blade, 32: Disk-shaped base metal portion, 34: Periphery, 36: Diamond abrasive grain layer base portion, 38: Multiple blades, 40: Diamond abrasive grain blade portion, 42: Insertion hole.

Claims

1. A plate-shaped quartz glass member for exposure to a film-forming process gas used in a semiconductor film-forming process, comprising: a plate-shaped quartz glass member body; a plurality of linear protrusions having a substantially rectangular cross section formed on at least a portion of the surface of the silica glass member body; a plurality of microcracks formed on at least one side surface of the linear protrusion; A quartz glass member for exposure to a film forming process gas, comprising: When the surface area with linear convex parts calculated from the dimensions is set to 1, a derived surface area calculated from a BET specific surface area obtained by a BET measurement method of the quartz glass member for exposure to a film-forming process gas on which the linear convex portions and the microcracks are formed; When the relationship is multiplied by B, B is 5 or more, Quartz glass component for exposure to film forming process gases.

2. The quartz glass member for exposure to a film forming process gas is Assuming that the surface of the quartz glass member main body is a quartz glass member having only flat surfaces, free of the linear convex portions and microcracks, the surface area of ​​only the flat surfaces calculated from the dimensions is set to 1. the dimensional surface area with linear protrusions calculated from the dimensions of the quartz glass member, which is assumed to have linear protrusions formed on at least a portion of the surface of the quartz glass member body and has a surface free of microcracks; Let the relationship be A times, When the surface area of ​​only the flat surface calculated from the above dimensions is 1, A derived surface area calculated from the BET specific surface area; When the relationship is multiplied by C, 2. The quartz glass member for exposure to a film-forming process gas according to claim 1, wherein the relationship A<B<C is satisfied.

3. The quartz glass member for exposure to a film forming process gas is B is more than twice as large as A, C is more than six times A, Satisfy the relationship of 3. The quartz glass member for exposure to a film-forming process gas according to claim 2.

4. Microcracks formed within a unit length of 0.1 mm on at least one side surface of the linear convex portion The average depth of each microcrack is 8 μm or more. The total depth of all microcracks per unit length is 50 μm or more; That is, The quartz glass member for exposure to a film-forming process gas according to claim 1.

5. 2. The quartz glass member for exposure to a film-forming process gas according to claim 1, wherein the microcracks are enlarged microcracks enlarged by etching.

6. The BET specific surface area of ​​the quartz glass member for exposure to a film-forming process gas, which includes the enlarged microcracks and is obtained by a BET measurement method, is the surface of the quartz glass member body is 7 times or more the BET specific surface area obtained by BET measurement when it is assumed that the quartz glass member has only flat surfaces, that is, has no linear convex portions or microcracks, and has entirely flat surfaces; The quartz glass member for exposure to a film-forming process gas according to claim 5.

7. The BET specific surface area of ​​the quartz glass member for exposure to a film-forming process gas containing the enlarged microcracks, as determined by a BET measurement method, is the surface of the quartz glass member body is 19 times or more larger than the BET specific surface area obtained by BET measurement when the quartz glass member body is assumed to have only flat surfaces, that is, free from the linear convex portions and microcracks, and has an entirely flat surface; The quartz glass member for exposure to a film-forming process gas according to claim 5.

8. 2. The quartz glass member for exposure to a film-forming process gas according to claim 1, wherein the thickness of the quartz glass member body is 1 to 1.5 mm, and the height of the linear convex portions is 0.6 mm or more and less than 1.5 mm.

9. A method for producing a quartz glass member for exposure to a film-forming process gas according to any one of claims 1 to 8, comprising: forming a linear convex portion having a substantially rectangular cross section on at least a portion of the silica glass member body using a grinding blade; forming a plurality of microcracks on at least one side surface of the linear convex portion; Including, The surface area of ​​the quartz glass member for exposure to the film-forming process gas is determined from the dimensions of the quartz glass member. The derived surface area of ​​the quartz glass member for exposure to a film-forming process gas, calculated from the BET specific surface area obtained by the BET measurement method, is larger than the derived surface area of ​​the quartz glass member for exposure to a film-forming process gas. A method for manufacturing a quartz glass member for exposure to a film-forming process gas.

10. 10. The method for manufacturing a quartz glass member for exposure to a film-forming process gas according to claim 9, further comprising the step of etching the quartz glass member body having the linear convex portions with microcracks formed therein to a depth of 0.1 μmm to 0.6 μmm, thereby enlarging the microcracks to form enlarged microcracks.

11. The method for producing a quartz glass member for exposure to a film-forming process gas according to claim 10, wherein the etching is carried out by an HF cleaning step.

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