Method for improving uniformity of wafer long film on RTP machine table

Abstract

The invention discloses a method for improving the uniformity of a wafer long film on an RTP machine table, and belongs to the technical field of semiconductor integrated circuit manufacturing. According to the method for improving the uniformity of the long film of the wafer on the RTP machine table, debugging of an aged lamp set in heating lamp sets or debugging of a newly-replaced heating lamp set is feasible, and the thickness value and the power value of the long film on the surface of the wafer are collected; and calculating the sensitivity value of each measurement point on the surface of the wafer by using the collected thickness value and power value, predicting the power value group of the heating lamp group needing to be adjusted by using the sensitivity value, and further adjusting the heating lamp group. According to the method, the number of wafers used during data acquisition is small, consumed time is short, and the working efficiency is improved; meanwhile, through the output power value group, the power of the aging lamp group or the newly replaced lamp group in the heating lamp group is adjusted to be increased or decreased, so that the heating temperature of the heating lamp group is in a stable state, and the uniformity of the film growing on the surface of the wafer under the heating lamp group is ensured.

Description

Technical Field

[0001] The invention discloses a method for improving the uniformity of film growth of a wafer on an RTP machine, and belongs to the technical field of semiconductor integrated circuit manufacturing. Background Art

[0002] Rapid thermal processing (RTP) process refers to such a type of single-wafer heat treatment process, and its purpose is to minimize the thermal budget of the process by lowering the temperature and shortening the time or only shortening the time. The RTP process is carried out in the RTP machine. The wafer is placed on the wafer support of the RTP machine. The heating lamp group above the wafer heats the wafer evenly, so that a film of uniform thickness is formed on the surface of the wafer. During the film growth process, the surface temperature of the wafer will be unevenly distributed due to the temperature changes of the multiple heating lamp groups above the wafer, which will cause uneven film growth on the wafer surface, affecting the product yield and causing a significant decrease in the qualified rate of film growth on the wafer surface.

[0003] In the actual production process, the heating lamp group on the RTP machine has the problem of uneven heating due to aging of the lamp group after long-term use; on the other hand, there is a temperature fluctuation caused by the increase or decrease of the heating temperature after replacing the new lamp group. In either case, the film growth on the wafer surface will be uneven. At present, the solutions for IC manufacturing plants (Fabrication) to deal with aging heating lamp groups or replace new heating lamp groups are usually:

[0004] 1. Use the compensation tool, namely the offset table, within a reasonable temperature range to increase or decrease the offset table to compensate for the power of the heating lamp group of the entire machine, and then adjust the heating temperature of the heating lamp group to change the temperature of the entire wafer so that the average thickness of the wafer film is within the required range. However, this method is usually suitable for the lamp group power that can make the wafer film uniform, and there may be a large offset problem for the newly replaced heating lamp group.

[0005] 2. For the new heating lamp group, the binary method is usually used to adjust the power of the corresponding lamp group. Adjust the OffsetTable or menu (Recipe) to modify the lamp group power, and then adjust the heating temperature of the heating lamp group. Each time you try to adjust, you need to place a bare silicon wafer (Bare Wafer) on the wafer stage, and then collect a set of wafer film thickness data until the adjusted lamp group power can make the film on the wafer grow evenly and the thickness of the film reaches a reasonable level. Using this method to debug the new heating lamp group requires continuous attempts, which takes a long time; each time the thickness data of the wafer film is collected, a bare wafer is required, resulting in a waste of wafers. Summary of the invention

[0006] In order to solve the technical problems such as uneven film thickness on the wafer surface caused by aging of the heating lamp group on the RTP machine and uneven heating temperature after replacement of the heating lamp group, the present invention proposes a method for improving the uniformity of wafer film growth on the RTP machine.

[0007] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0008] Methods to improve the uniformity of wafer film growth on RTP machines, such as Figure 1 As shown, during the normal use of the heating lamp group, some heating lamp groups will age. When debugging the heating lamp group aging, the specific steps include:

[0009] S11, when the airflow of the RTP machine is stable, the Base Line Recipe is set to grow a film on the surface of Wafer 1 under the Base Line condition, and the Power value set under the Base Line condition is recorded. The Line Scan collects the thickness (THK) data of the film grown on the surface of Wafer 1;

[0010] S12, adjusting the power value of each zone in the heating lamp group and recording it; performing a split experiment of the heating lamp group in each zone and collecting THK data;

[0011] S13, calculating the THK sensitivity of the film grown on wafer 1 in each zone of the heating lamp group, and the calculation formula is:

[0012] Sensitivity (Zone i) =ΔTHK (Zone i) / (ΔPower (Zone i) );

[0013] S14, use planning to solve the constraints and calculate the adjustment Power difference of each measuring point 2, the calculation formula is:

[0014] THK (测量点位的预测值) =THK (Base Line) +ΔTHK (h-1) +……+ΔTHK (h-i) =THK (Base Line) +X×A;

[0015] or

[0016] When debugging a new heating lamp set, the specific steps include:

[0017] S21, when the airflow of the RTP machine is stable, the Base Line Recipe is set to grow a film on the surface of Wafer 1 under the Base Line condition, and the Power value set under the Base Line condition is recorded. The Line Scan collects the thickness (THK) data of the film grown on the surface of Wafer 1.

[0018] S22, adjusting the power value of each zone in the heating lamp group, performing a split experiment of the heating lamp group in each zone, and collecting THK data;

[0019] S23, calculating the THK sensitivity of the film grown on wafer 1 in each zone of the heating lamp group, and the calculation formula is:

[0020] Sensitivity (Zone i) =ΔTHK (Zone i) / (ΔPower (Zone i) );

[0021] S24, replace the new heating lamp group, after the RTP machine airflow is stable, collect the THK data of the film on the surface of wafer 1 obtained by Line Scan, and calculate the THK data collected under the Base Line condition and the THK data after replacing the new heating lamp group. The calculation formula is:

[0022] THK (差值) =THK (Base Line) -THK (新加热灯组) ;

[0023] S25, specify the thickness value of the film on the surface of wafer 1 and the planning and solving constraints, and calculate the adjustment Power difference of each measuring point 2, the calculation formula is:

[0024] THK (测量点位的预测值) =THK (Base Line) +ΔTHK (h-1) +……+ΔTHK (h-i) +THK (差值)

[0025] =THK (Base Line) +X×A+THK (差值) .

[0026] Beneficial effects of the present invention: The present invention proposes a method for improving the uniformity of film growth on a wafer on an RTP machine. Through the methods of steps S11, S12 or S21, S22 of the present invention, the data of film thickness on the surface of the wafer under the heating lamp group and the data of debugging power are collected. In the process of collecting data, the number of wafers required is very small, only 2 wafers are required, thereby avoiding the phenomenon of wasting wafers when debugging the heating lamp group in the prior art; and the time required for data collection is short, thereby improving work efficiency; in step S13 or S23 of the present invention, the sensitivity value corresponding to each measuring point on the wafer is calculated through the above-mentioned collected data, and when the power of the heating lamp group is debugged, it can be adjusted according to the sensitivity value, so that the adjustment of the heating lamp group is convenient and quick. (Before debugging the heating lamp group, the above-mentioned collection and calculation of sensitivity values ​​only need to be performed once, and there is no need to collect and adjust the data once.) When adjusting the power of the aged heating lamp group in the heating lamp group, through the calculation formula shown in steps S14 and S25, and using the wafer thickness value, Base Line thickness value and calculated sensitivity value collected in steps S11, S12 or S21, S22, it is possible to estimate the thickness value of the film that needs to be increased or decreased on the wafer surface under the aged lamp group or the newly replaced lamp group, and then accurately output the adjusted power value group for each measuring point; through the output power value group, the power of the aged lamp group or the newly replaced lamp group in the heating lamp group is adjusted to increase or decrease, so that the heating temperature of the heating lamp group is in a stable state, thereby ensuring the uniformity of the film growth on the wafer surface under the heating lamp group. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The present invention is a flowchart for debugging an aging lamp group in a heating lamp group, and the figure is also used as a summary figure.

[0028] Figure 2 Schematic diagram of the measurement point distribution of the present invention.

[0029] Figure 3 This is a comparison curve diagram of the film thickness on the wafer surface before and after the aging lamp group is adjusted according to the present invention.

[0030] Figure 4 This is a comparison curve diagram of the film thickness on the wafer surface before and after adjustment of the newly replaced heating lamp group according to the present invention. DETAILED DESCRIPTION

[0031] The present invention is further described.

[0032] During the normal use of the heating lamp group, some heating lamp groups will age. For some aged heating lamp groups, regular inspection and calibration are required. When debugging the aging heating lamp group, such as Figure 1As shown, the specific steps include:

[0033] S11, when the airflow of the RTP machine is stable, the Base Line Recipe is set to grow a film on the surface of Wafer 1 under the Base Line condition, and the Power value set under the Base Line condition is recorded. The Line Scan collects the thickness (THK) data of the film grown on the surface of Wafer 1;

[0034] Specifically, a clean wafer 1 is placed in a cleaning machine to wash away particles on the surface for later use. When the airflow of the RTP machine is stable, that is, the airflow is laminar, the wafer 1 is placed in the atmospheric pressure chamber of the RTP machine and is located below the heating lamp group. The BaseLine Recipe is set under the Base Line condition to grow a film on the surface of the wafer 1. Then, the wafer 1 with the film grown is transferred to a machine for measuring the thickness of the wafer 1. When Line Scan collects THK data of the film grown on the surface of the wafer 1, as shown in FIG. Figure 2 As shown, usually 13 to 121 measurement points 2 are uniformly selected along the diameter of the wafer 1 to collect its THK data, and the measurement point 2 is represented by h. More preferably, 49 measurement points 2 are uniformly selected along the diameter of the wafer 1 to collect the data.

[0035] S12, adjusting the power value of each zone in the heating lamp group and recording it; performing a split experiment of the heating lamp group in each zone and collecting THK data;

[0036] Specifically, each Zone in the heating lamp group is represented by i, where i is 1 to 15, that is, the heating lamp group has 1 to 15 Zones. The power values ​​of the 15 Zones in the heating lamp group are adjusted one by one, and then a Split experiment of the heating lamp group in each Zone is performed, and the corresponding THK data of the film growth on the surface of wafer 1 is collected. For example, taking Zone 1 in the heating lamp group as an example, when Zone 1 is set in the Base Line Recipe, the Power used is 1000W. When doing the Split experiment now, the Power of Zone 1 is modified to 800W, so that the Power difference between the modified and the modified is 200, and the modified Power value is recorded; when the airflow of the RTP machine is stable, wafer 1 is placed in the atmospheric pressure chamber of the RTP machine to grow a film on the surface of wafer 1, and then the wafer 1 with the film growth is transferred to the machine for measuring the thickness of wafer 1, and 49 measurement points 2 are evenly selected along the diameter of wafer 1 to perform Line Scan to collect the THK data of the film growth, and the THK value of each measurement point 2 is recorded; the Split experiments of the remaining 14 zones in the heating lamp group are also conducted in the same way as the decomposition experiment of Zone 1, and the corresponding Power values ​​and THK values ​​are recorded.

[0037] S13, calculating the THK sensitivity of the film of wafer 1 in each zone of the heating lamp group, and the calculation formula is:

[0038] Sensitivity (Zone h-i) =ΔTHK (Zone h-i) / (ΔPower (Zone h-i) );

[0039] Among them, ΔTHK (Zone h-i) is the difference between the THK data of the film on the surface of wafer 1 collected under the baseline condition and the THK data of the film on the surface of wafer 1 collected in the Split experiment at the hth measurement point 2 of the heating lamp group with Zone i. Its ΔTHK (Zone h-i) The calculation formula is:

[0040] ΔTHK (Zone h-i) =THK (Base Line) -THK (Zone h-i)

[0041] ΔPower( Zone h-i ) is the difference between the Power value recorded under the baseline condition and the adjusted Power value of the heating lamp group in Zone i at the hth measuring point 2, and its ΔPower (Zone h-i) The calculation formula is:

[0042] ΔPower (Zone h-i) =Power (Base Line) -Power (Zone h-i) .

[0043] Specifically, the 49 measurement points 2 selected on the wafer 1 are all based on the zero level. The THK values ​​collected in the S11 and S12 steps (under the Base Line condition and in the Split experiment) are all adjusted down to the zero level, and then the formula is used:

[0044] ΔTHK (Zone h-i) =THK (Base Line) -THK (Zone h-i)

[0045] Calculate the THK difference of each measuring point 2 in each Zone and record it; then, based on the Power value set under the Base Line conditions recorded in steps S11 and S12 and the Power value adjusted for each Zone in the Split experiment, use the formula:

[0046] ΔPower (Zone h-i) =Power (Base Line) -Power (Zone h-i)

[0047] Calculate the Power difference of each measuring point 2 in each Zone and record it; finally, according to the above calculation results of the THK difference and Power difference of each measuring point 2 in each Zone, substitute the results into the formula:

[0048] Sensitivity (Zone h-i) =ΔTHK (Zone h-i) / (ΔPower (Zone h-i) )

[0049] Calculate the sensitivity value of each measuring point 2 in each zone, that is, the linear relationship between the THK difference and the Power difference, and finally record the calculation results.

[0050] S14, use planning to solve the constraints and calculate the adjustment Power difference of each measuring point 2, the calculation formula is:

[0051] THK (测量点位的预测值) =THK (Base Line) +ΔTHK (h-1) +……+ΔTHK (h-i)

[0052] =THK (Base Line) +X×A;

[0053] Specifically, when debugging the Power value of the aged heating lamp group in the heating lamp group, the planning and solving constraints are used to calculate the adjusted Power difference of each measuring point 2; wherein, the planning and solving constraints include the adjusted power value and the thickness value that needs to be increased at the measuring point 2; wherein, the adjusted power value range is -200 to 200; the adjustment range of the thickness value that needs to be increased at the measuring point 2 is based on the demand for the predicted THK value to be increased, and the upper and lower limits of the thickness that needs to be increased based on the THK value of the BaseLine for each measuring point 2 are set. By constraining the adjusted power value and the thickness value that needs to be increased at the measuring point 2, the thickness of the film grown on the surface of the wafer 1 under the adjusted heating lamp group is uniform and the fluctuation range is small; then, the calculation formula in step S14 is used to calculate the predicted THK value of the corresponding measuring point 2, and the adjusted Power value of each Zone in the heating lamp group is solved, and the predicted THK value of the measuring point 2 is compared with its BaseLine. Line, and then the optimal solution is obtained, so that the temperature of the heating lamp group after adjustment is more stable than the temperature of the heating lamp group before adjustment, so as to ensure uniform film growth on the surface of wafer 1 under the heating lamp group. Figure 3 As shown, the thickness of the long film at each measuring point 2 has a smaller fluctuation than the thickness of the long film on the surface of the wafer 1 before adjustment.

[0054] Because the light of the heating lamp group is scattered, when debugging the aging lamp group in the heating lamp group, the heating temperature of the heating lamp groups in other zones will also affect the aging lamp group. Therefore, when predicting the thickness value of each measuring point 2, it is necessary to add the THK differences of the 15 zones of the measuring point 2, and then add it to the THK value of the Base Line to obtain the predicted value of the measuring point 2 in the aging lamp group, using the calculation formula in the above step S14:

[0055] THK (测量点位的预测值) =THK (Base Line) +ΔTHK (h-1) +……+ΔTHK (h-i)

[0056] =THK (Base Line) +X×A

[0057] Calculate. Among them, ΔTHK (h-i) represents the thickness difference of the hth measurement point 2 in Zone i, X represents the power value group, then

[0058] X=[x1,x2,x3,x4,x5,x6,…,x j ];

[0059] Where j is the column where each adjusted Power difference value in the power value group is located, and j is 1 to 15;

[0060] A represents the sensitivity value and relative position, that is, the location of the sensitivity value of measurement point 2 in each zone.

[0061]

[0062] Therefore, THK (测量点位的预测值) =THK (Base Line) +X×A

[0063] =THK (Base Line) +x1a (h,1) +x2a (h,2) +x3a (h,3) +x4a (h,4) +x5a (h,5) +x6a (h,6) +x7a (h,7) +x8a (h,8) +x9a (h,9) +x 10 a (h,10) +

[0064] x 11 a (h,11) +x 12 a (h,12) +x 13 a (h,13) +x 14 a (h,14) +x 15 a (h,15) ;

[0065] Wherein, h is the hth measurement point in measurement point 2;

[0066] Therefore, ΔTHK (h-1) =x1a (h,1)。

[0067] If the solution of the power value group output according to the above formula cannot make the thickness of the film on the surface of wafer 1 more uniform and the fluctuation of thickness smaller, then the solution of the power value group output is not a useful solution, and the planning solution constraints need to be readjusted, and the power value group is calculated again until a useful solution is solved. Finally, according to the useful solution of the power value group solved, the power of the heating lamp group is adjusted to make the temperature of the adjusted heating lamp group more stable, ensure that the thickness of the film on the surface of wafer 1 is more uniform, and the fluctuation of the thickness of the film at each measuring point 2 is smaller, so that the efficiency of the film growth process on the surface of wafer 1 is higher.

[0068] The fifth measuring point in measuring point 2 needs to be increased The output power value group is solved by taking the THK value of the long film as an example. Set the constraint conditions for the planning solution, limit the Power value that needs to be adjusted for the heating lamp group to the range of -200 to 200, and constrain the fluctuation range of the thickness value of each measuring point 2 based on the THK value of the Base Line. The constraint range is Then use the above calculation formula:

[0069] THK (测量点位的预测值) =THK (BaseLine) +x1a (5,1) +x2a (5,2) +x3a (5,3) +x4a (5,4) +x5a (5,5) +x6a (5,6) +x7a (5,7) +x8a (5,8) +x9a (5,9)

[0070] +x 10 a (5,10) +x 11 a (5,11) +x 12 a (5,12) +x 13 a (5,13) +x 14 a (5,14) +x 15 a (5,15) ; Solve the corresponding power value group and the predicted THK value of the measuring point 2, and then adjust the power of the heating lamp group according to the solution of the solved power value group.

[0071] When debugging a new heating lamp group replaced in one zone of the heating lamp group, the specific steps include:

[0072] S21, when the airflow of the RTP machine is stable, the Base Line Recipe is set to grow a film on the surface of Wafer 1 under the Base Line condition, and the power (Power) set under the Base Line condition is recorded. The Line Scan collects the thickness (THK) data of the film grown on the surface of Wafer 1;

[0073] Specifically, a clean wafer 1 is placed in a cleaning machine to wash away particles on the surface for later use. When the airflow of the RTP machine is stable, that is, the airflow is laminar, the wafer 1 is placed in the atmospheric pressure chamber of the RTP machine and is located below the heating lamp group. The BaseLine Recipe is set under the Base Line condition to grow a film on the surface of the wafer 1. The wafer 1 on which the film growth has been completed is then transferred to a machine for measuring the thickness of the wafer 1. When Line Scan collects THK data of the film grown on the surface of the wafer 1, 13 to 121 measurement points 2 are usually uniformly selected along the diameter of the wafer 1 to collect its THK data. The measurement point 2 is represented by h. More preferably, 49 measurement points 2 are uniformly selected along the diameter of the wafer 1 for collection.

[0074] S22, adjusting the power value of each zone in the heating lamp group and recording it; performing a split experiment of the heating lamp group in each zone and collecting THK data;

[0075] Specifically, each Zone in the heating lamp group is represented by i, where i is 1 to 15, that is, the heating lamp group has 1 to 15 Zones. The power values ​​of the 15 Zones in the heating lamp group are adjusted one by one, and then a Split experiment of the heating lamp group in each Zone is performed, and the corresponding THK data of the film growth on the surface of wafer 1 is collected. For example, taking Zone 1 in the heating lamp group as an example, when Zone 1 is set in the Base Line Recipe, the Power used is 1000W. When doing the Split experiment now, the Power of Zone 1 is modified to 800W, so that the Power difference between the modified and the modified is 200, and the modified Power value is recorded; when the airflow of the RTP machine is stable, wafer 1 is placed in the atmospheric pressure chamber of the RTP machine to grow a film on the surface of wafer 1, and then the wafer 1 with the film growth is transferred to the machine for measuring the thickness of wafer 1, and 49 measurement points 2 are evenly selected along the diameter of wafer 1 to perform Line Scan to collect the THK data of the film growth, and the THK value of each measurement point 2 is recorded; the Split experiments of the remaining 14 zones in the heating lamp group are also conducted in the same way as the decomposition experiment of Zone 1, and the corresponding Power values ​​and THK values ​​are recorded.

[0076] S23, calculating the THK sensitivity of the film grown on wafer 1 in each zone of the heating lamp group, and the calculation formula is:

[0077] Sensitivity (Zone h-i) =ΔTHK (Zone h-i) / (ΔPower (Zone h-i) );

[0078] Among them, ΔTHK (Zone h-i) is the difference between the THK data of the film on the surface of wafer 1 collected under the baseline condition and the THK data of the film on the surface of wafer 1 collected in the Split experiment at the hth measurement point 2 of the heating lamp group with Zone i. Its ΔTHK (Zone h-i) The calculation formula is:

[0079] ΔTHK (Zone h-i) =THK (Base Line) -THK (Zone h-i)

[0080] ΔPower (Zone h-i) The ΔPower is the difference between the Power value recorded under the baseline condition and the adjusted Power value of the heating lamp group in Zone i at the hth measurement point 2. (Zone h-i) The calculation formula is:

[0081] ΔPower (Zone h-i) =Power (Base Line) -Power (Zone h-i) .

[0082] Specifically, the 49 measurement points 2 selected on the wafer 1 are all based on the zero level. The THK values ​​collected in the S11 and S12 steps (under the Base Line condition and in the Split experiment) are all adjusted down to the zero level, and then the formula is used:

[0083] ΔTHK (Zone h-i) =THK (Base Line) -THK (Zone h-i)

[0084] Calculate the THK difference of each measuring point 2 in each Zone and record it; then, based on the Power value set under the Base Line conditions recorded in steps S11 and S12 and the Power value adjusted for each Zone in the Split experiment, use the formula:

[0085] ΔPower (Zone h-i) =Power (Base Line)-Power (Zone h-i)

[0086] Calculate the Power difference of each measuring point 2 in each Zone and record it; finally, according to the above calculation results of the THK difference and Power difference of each measuring point 2 in each Zone, substitute the results into the formula:

[0087] Sensitivity (Zone h-i) =ΔTHK (Zone h-i) / (ΔPower (Zone h-i) )

[0088] Calculate the sensitivity value of each measuring point 2 in each zone, that is, the linear relationship between the THK difference and the Power difference, and finally record the calculation results.

[0089] S24, replace the new heating lamp group, after the RTP machine airflow is stable, collect the THK data of the film on the surface of wafer 1 obtained by Line Scan, and calculate the THK data collected under the Base Line condition and the THK data after replacing the new heating lamp group. The calculation formula is:

[0090] THK (差值) =THK (Base Line) -THK (新加热灯组) ;

[0091] Specifically, after replacing the new heating lamp group, the temperature irradiated to the surface of wafer 1 will change, which will cause the THK of the film grown on the surface of wafer 1 to fluctuate more. Therefore, after replacing the heating lamp group, when the airflow of the RTP machine is stable, that is, when the airflow is laminar, the cleaned wafer 1 is placed in the normal pressure chamber of the RTP machine to grow a film on the surface of wafer 1. Then, the wafer 1 with the film grown is transferred to the machine for measuring the thickness of wafer 1, and 49 measurement points 2 are evenly selected along the diameter of wafer 1 to perform Line Scan to collect THK data of the film grown on the surface of wafer 1. Then, according to the calculation formula: THK (差值) =THK (Base Line) -THK (新加热灯组) Calculate the difference between the THK value collected at each measuring point 2 under the Base Line condition and the THK value after replacing the new heating lamp group.

[0092] S25, use planning to solve the constraints and calculate the adjustment Power difference of each measuring point 2, the calculation formula is:

[0093] THK (测量点位的预测值) =THK (Base Line) +ΔTHK (h-1) +……+ΔTHK (h-i) +THK (新加热灯组)

[0094] =THK (Base Line) +X×A+THK (新加热灯组) ;

[0095] Specifically, when debugging the Power value of the newly replaced heating lamp group in the heating lamp group, the planning and solving constraints are used to calculate the adjusted Power difference of each measuring point 2; wherein, the planning and solving constraints include the adjusted power value and the thickness value that needs to be increased at the measuring point 2; wherein, the adjusted power value range is -200 to 200; the adjustment range of the thickness value that needs to be increased at the measuring point 2 is set according to the demand for the predicted THK value that needs to be increased, and the thickness that needs to be increased based on the THK value of the BaseLine of each measuring point 2 is set. By constraining the adjusted power value and the thickness value that needs to be increased at the measuring point 2, the thickness of the film grown on the surface of the wafer 1 under the newly replaced heating lamp group is uniform and the fluctuation range is small; then, the calculation formula in step S25 is used to calculate the predicted THK value of the corresponding measuring point 2, and the adjusted Power value of each Zone in the heating lamp group is solved, and the predicted THK value of the measuring point 2 is compared with its BaseLine. Line, and then the optimal solution is obtained, so that the temperature of the newly replaced heating lamp group is more stable than the temperature of the heating lamp group before replacement, so as to ensure uniform film growth on the surface of wafer 1 under the newly replaced heating lamp group. Figure 4 As shown, the thickness of the long film at each measuring point 2 has a smaller fluctuation than the thickness of the long film on the surface of the wafer 1 before replacement.

[0096] Because the light of the heating lamp group is scattered, when debugging the newly replaced heating lamp group in the heating lamp group, the heating temperature of the heating lamp groups in other zones will also affect the newly replaced heating lamp group. Therefore, when predicting the thickness value of each measuring point 2, it is necessary to add the THK difference of the 15 zones of the measuring point 2, and then add the THK difference in step S24 and the THK value of the Base Line to obtain the predicted value of the measuring point 2 in the newly replaced heating lamp group, using the calculation formula in the above step S25:

[0097] THK (测量点位的预测值) =THK (Base Line) +ΔTHK (h-1) +……+ΔTHK (h-i)+THK (新加热灯组)

[0098] =THK (Base Line) +X×A+THK (新加热灯组)

[0099] Calculate. Among them, ΔTHK (h-i) represents the thickness difference of the hth measurement point 2 in Zone i, X represents the power value group, then

[0100] X=[x1,x2,x3,x4,x5,x6,…,x j ];

[0101] Where j is the column where each adjusted Power difference value in the power value group is located, and j is 1 to 15;

[0102] A represents the sensitivity value and relative position, that is, the location of the sensitivity value of measurement point 2 in each zone.

[0103]

[0104] Therefore, THK (测量点位的预测值) =THK (Base Line) +X×A+THK (新加热灯组) =THK (Base Line) +x1a (h,1) +x2a (h,2) +x3a (h,3) +x4a (h,4) +x5a (h,5) +x6a (h,6) +x7a (h,7) +x8a (h,8) +x9a (h,9) +x 10 a (h,10) +

[0105] x 11 a (h,11) +x 12 a (h,12) +x 13 a (h,13) +x 14 a (h,14) +x 15 a (h,15) +THK (新加热灯组) ;

[0106] Wherein, h is the hth measurement point in measurement point 2;

[0107] Therefore, ΔTHK(h-1) =x1a (h,1) .

[0108] If the solution of the power value group output according to the above formula cannot make the thickness of the film on the surface of wafer 1 more uniform and the fluctuation of thickness smaller, then the solution of the power value group output is not a useful solution, and it is necessary to readjust the planning and solving constraints and calculate the power value group again until a useful solution is solved. Finally, according to the useful solution of the power value group solved, the power of the heating lamp group is adjusted to make the temperature of the adjusted heating lamp group more stable, ensure that the thickness of the film on the surface of wafer 1 is more uniform, and the fluctuation of the thickness of the film at each measuring point 2 is smaller, so that the efficiency of the film growth process on the wafer surface is higher.

[0109] For the newly replaced heating lamp group, the 7th measuring point in the measuring point 2 of Zone 8 needs to be increased. The output power value group is solved by taking the THK value of the Base Line as an example. Set the constraint conditions for the planning solution, and limit the Power value that needs to be adjusted for the newly replaced heating lamp group to the range of -200 to 200. The fluctuation range of the thickness value of each measuring point 2 is constrained based on the THK value of the Base Line. The constraint range is Then use the above calculation formula: THK (测量点位的预测值) =THK (Base Line) +x1a (7,1) +x2a (7,2) +x3a (7,3) +x4a (7,4) +x5a (7,5) +x6a (7,6) +x7a (7,7) +x8a (7,8) +x9a (7,9) +x 10 a (7,10) +x 11 a (7,11) +x 12 a (7, 12)

[0110] +x 13 a (7,13) +x 14 a (7,14) +x 15 a (7,15) +THK (新加热灯组) ; Solve the corresponding power value group and the predicted THK value of the measuring point 2, and then adjust the power of the newly replaced heating lamp group according to the solution of the solved power value group.

[0111] The above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A method for improving the uniformity of film growth on a wafer on an RTP machine, characterized in that: During the normal use of the heating lamp group, some heating lamp groups will age. When debugging the heating lamp group aging, the specific steps include: S11, when the airflow of the RTP machine is stable, the base menu (Base Line Recipe) is set to grow a film on the surface of the wafer (1) under the base line (Base Line) condition, and the power (Power) value set under the base line condition is recorded, and the line scan (LineScan) collects the thickness (THK) data of the film grown on the surface of the wafer (1); S12, adjusting the power value of each zone in the heating lamp group and recording it; performing a split experiment of the heating lamp group in each zone and collecting THK data; S13, calculating the THK sensitivity of the film grown on the wafer (1) in each zone of the heating lamp group, and the calculation formula is: Sensitivity (Zonei) =ΔTHK (Zonei) / (ΔPower (Zonei) ); S14, using planning to solve the constraints and calculate the adjustment Power difference of each measuring point (2), the calculation formula is: THK (测量点位的预测值) =THK (BaseLine) +ΔTHK (h-1) +……+ΔTHK (h-i) =THK (BaseLine) +X×A; or When debugging a new heating lamp set, the specific steps include: S21, when the airflow of the RTP machine is stable, the base menu (Base Line Recipe) is set to grow a film on the surface of the wafer (1) under the base line (Base Line) condition, and the power (Power) value set under the base line condition is recorded, and the line scan (LineScan) collects the thickness (THK) data of the film grown on the surface of the wafer (1); S22, adjusting the power value of each zone in the heating lamp group, performing a split experiment of the heating lamp group in each zone, and collecting THK data; S23, calculating the THK sensitivity of the film grown on the wafer (1) in each zone of the heating lamp group, and the calculation formula is: Sensitivity (Zoneh-i) =ΔTHK (Zoneh-i) / (ΔPower (Zoneh-i) ); S24, replace the new heating lamp group, after the RTP machine airflow is stable, collect the THK data of the film on the surface of the wafer (1) obtained by Line Scan, and calculate the THK data collected under the Base Line condition and the THK data after replacing the new heating lamp group. The calculation formula is: THK (差值) =THK (BaseLine) -THK (新加热灯组) ; S25, specifying the thickness of the film on the surface of the wafer (1) and the planning and solving constraints, and calculating the adjustment Power difference of each measuring point (2), the calculation formula is: THK (测量点位的预测值) =THK (BaseLine) +ΔTHK (h-1) +……+ΔTHK (h-i) =THK (BaseLine) +X×A+THK (差值) 。 2. The method for improving the uniformity of film growth of wafers on an RTP machine according to claim 1, characterized in that: In steps S11 and S21, when collecting THK data of the film grown on the surface of the wafer (1), 13 to 121 measuring points (2) are uniformly selected along the diameter of the wafer (1) for collection, and the measuring points (2) are represented by h.

3. The method for improving the uniformity of film growth of wafers on an RTP machine according to claim 1, characterized in that: In steps S11 and S21, when collecting THK data of the film grown on the surface of the wafer (1), 49 measurement points (2) are uniformly selected along the diameter of the wafer (1) for collection.

4. The method for improving the uniformity of film growth of wafers on an RTP machine according to claim 1, characterized in that: In steps S12 and S22, each Zone in the heating lamp group is represented by i, where i ranges from 1 to 15.

5. The method for improving the uniformity of film growth of wafers on an RTP machine according to claim 1, characterized in that: In steps S13 and S23, ΔTHK (Zonei) is the difference between the THK data of the film grown on the surface of wafer (1) collected under the baseline condition and the THK data of the film grown on the surface of wafer (1) collected in the Split experiment at the hth measurement point (2) of the heating lamp group in Zone i. Its ΔTHK (Zoneh-i) The calculation formula is: ΔTHK (Zoneh-i) =THK (BaseLine) -THK (Zoneh-i) ΔPower(Zone h-i ) is the difference between the Power value recorded under the baseline condition and the adjusted Power value of the heating lamp group in Zone i at the hth measurement point (2), and its ΔPower (Zoneh-i) The calculation formula is: ΔPower (Zoneh-i) =Power (BaseLine) -Power (Zoneh-i) 。 6. The method for improving the uniformity of film growth of wafers on an RTP machine according to claim 1, characterized in that: In steps S14 and S25, the planning and solving constraints include the adjusted power value and the thickness value that needs to be increased at the measuring point (2); The adjustable power value range is -200 to 200. The thickness value adjustment range of the measuring point (2) needs to be increased. The upper and lower limits of the thickness that needs to be increased at each measuring point (2) based on the THK value of the Base Line are set according to the demand for the predicted THK value to be increased.

7. The method for improving the uniformity of film growth of wafers on an RTP machine according to claim 1, characterized in that: In steps S14 and S25, the calculation formula is X×A, where X is the power value group, then X=[x1,x2,x3,x4,x5,x6,……,x j ]; Where j is the column where each adjusted Power difference value in the power value group is located, and j is 1 to 15; A is the sensitivity value and the corresponding position, that is, the position of the sensitivity value of the measurement point (2) of each zone.

8. The method for improving the uniformity of film growth of wafers on an RTP machine according to claim 7, characterized in that: In step S14, the calculation formula is: THK (测量点位的预测值) =THK (BaseLine) +ΔTHK (h-1) +……+ΔTHK (h-i) =THK (BaseLine) +X×A =THK (BaseLine) +x1a (h,1) +x2a (h,2) +x3a (h,3) +x4a (h,4) +x5a (h,5) +x6a (h,6) +x7a (h,7) +x8a (h,8) +x9a (h,9) +x 10 a (h,10) +x 11 a (h,11) +x 12 a (h,12) +x 13 a (h,13) +x 14 a (h,14) +x 15 a (h,15) 。 9. The method for improving the uniformity of film growth of wafers on an RTP machine according to claim 7, characterized in that: In step S25, the calculation formula is: THK (测量点位的预测值) =THK (BaseLine) +ΔTHK (h-1) +……+ΔTHK (h-i) +THK (新加热灯组) =THK (BaseLine) +X×A+THK (新加热灯组) =THK (BaseLine) +x1a (h,1) +x2a (h,2) +x3a (h,3) +x4a (h,4) +x5a (h,5) +x6a (h,6) +x7a (h,7) +x8a (h,8) +x9a (h,9) +x 10 a (h,10) +x 11 a (h,11) +x 12 a (h,12) +x 13 a (h,13) +x 14 a (h,14) +x 15 a (h,15) +THK (新加热灯组) 。

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