JP3438558B2 - Semiconductor wafer etching equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a semiconductor wafer etching apparatus for manufacturing semiconductor sensors such as pressure sensors and acceleration sensors.

[0002]

2. Description of the Related Art For example, as a pressure sensor and an acceleration sensor, there is a semiconductor sensor manufactured by using a chip obtained by processing a semiconductor into a diaphragm shape or the like. As shown in FIGS. 6A and 6B, this semiconductor sensor chip 20 is provided with recesses 21 of about several hundreds to several thousands on the semiconductor wafer 2 by etching, and is then cut according to the recess formation position. It is manufactured by

Further, as shown in FIG. 6, the semiconductor wafer 2 is composed of a circuit surface (non-processed surface) 29 forming a normal semiconductor circuit 290 and an etching processed surface (processed surface) 28 on which a sensor shape is provided. Has been done. Then, by changing the shape of the mask 3 attached to the processed surface 28, the shape of the recess 21 suitable for the function of the sensor can be obtained.

As the shape of the tip 20, as shown in FIG. 7, one for a pressure sensor having a concave portion 21 in which the center of the tip is concave, or as shown in FIG. 8, an island-shaped bulge 215 is left in the center of the tip. There are various shapes such as those for an acceleration sensor in which the concave portion 21 is formed by carving the periphery thereof. These are formed by devising the mask 3 and melting and removing the non-mask portion with an anisotropic etching solution such as potassium hydroxide.

The performance of various sensors using these chips 20 is determined by the accuracy of the thickness T of the bottom of the recess 21. Therefore, when etching the semiconductor wafer 2, the most important issue is how to accurately control the thickness T of the bottom of the recess 21.

Next, FIG. 9 shows an etching processing apparatus 9 using a conventional anisotropic etching solution. As shown in the figure, the etching apparatus 9 includes an etching bath 93 for containing the etching liquid 8 and a heater 9 for heating the etching bath 93 from below.
4 and. Further, in the etching bath 93, a temperature sensor 941 for controlling the heater 94 and an etching solution 8
An agitator 95 for agitating the semiconductor wafer 2 and a holder 96 for exposing and holding the processed surface 28 of the semiconductor wafer 2 in the etching liquid 8 are provided. A power source 97 is provided between the semiconductor wafer 2 and the electrode 971 immersed in the etching solution 8 in preparation for performing so-called electrochemical stop etching.

When the semiconductor wafer 2 is etched by using the etching apparatus 9, as shown in FIG.
As shown in, the heater 8 heats the etching solution 8 contained in the etching bath 93 to a predetermined temperature. At this time, the heater 94 is accurately controlled using the data from the temperature sensor 941 immersed in the etching liquid 8.
Next, with the etching liquid 8 maintained at a predetermined temperature,
The semiconductor wafer 2 set on the holding jig 96 is immersed in the etching solution 8. As a result, the semiconductor wafer 2 is gradually etched.

[0008]

By the way, as a method of knowing that the thickness T of the bottom portion of the concave portion 21 of the semiconductor wafer 2 has reached a target thickness when performing the etching processing by the conventional etching processing apparatus 9, the conventional method 2 is used. Two methods have been devised and implemented. The first method is a time management method, in which the etching amount (etching rate) per time is measured in advance and estimated from this.

Specifically, as shown in FIG. 10, a graph is created with the vertical axis representing the etching amount and the horizontal axis representing the etching time. Then, with the value obtained by subtracting the target thickness T from the original thickness of the semiconductor wafer 2 as the etching amount E, the etching time t1 is obtained from the graph of FIG. 10 to control the immersion time. Then, after t1 time has elapsed from the start of the etching process, the etching process is stopped assuming that the target thickness T is reached.

In this method, reproducibility of etching rate is very important. However, this etching rate is difficult to control because it reacts sensitively to the temperature and concentration of the etching solution, and it is difficult to satisfy the accuracy required in recent years with a single etching process. for that reason,
The etching process is performed several times, and the thickness measurement and the etching process are repeated. Therefore, a lot of man-hours are required.

The second method is an electrochemical stop etching method. In this method, as shown in FIG. 9, etching is performed while applying electricity to the circuit surface 18 of the semiconductor wafer 2 by a power source 97, and a change in current during etching is monitored by an ammeter 972. As a result, the graph as shown in FIG. 11 is obtained. In the graph of the figure, the vertical axis represents the current value during etching and the horizontal axis represents the elapsed etching time.

As is known from the figure, the current in this case rises as the etching progresses and shows a peak p near the target thickness. From this point, the etching process is stopped after waiting a certain time t2. . In this method, the influence of the etching rate is less than that of the time management, so that the thickness T can be obtained with relatively high accuracy. However, in principle, it is impossible to make thicker than 20 μm or thinner than the epi layer (layer for forming the semiconductor circuit), and the accuracy can be obtained in principle, depending on the accuracy of the thickness variation of the epi layer. There are problems such as not being able to. Therefore, in the case of this method as well, a step of performing the etching process and the actual measurement of the thickness in two or more times is required.

The present invention has been made in view of the above conventional problems, and an etching processing apparatus for a semiconductor wafer capable of controlling the etching amount with high precision and stopping the etching processing at an optimum timing. It is the one we are trying to provide.

[0014]

According to a first aspect of the present invention, there is provided an etching pot in which a semiconductor wafer is used as a part of a bottom plate or a side wall, and a processed surface of the semiconductor wafer is an inner surface and a non-processed surface is an outer surface. , An etching head having a stirring means and a heating means for the etching liquid placed in the etching pot, a thickness measuring sensor arranged facing the non-processed surface of the semiconductor wafer, and the thickness measuring sensor in any three-dimensional direction. And a sensor moving device for moving the semiconductor wafer to a position, and the etching processing of the semiconductor wafer is performed while measuring the thickness of the semiconductor wafer from the non-processed surface side of the semiconductor wafer by the thickness measuring sensor. Etching of a semiconductor wafer, characterized in that the etching process is stopped when the thickness of the semiconductor wafer reaches a predetermined thickness. In the processing equipment.

What is most noticeable in the present invention is that the semiconductor wafer to be processed is provided as a part of the etching pot, and the thickness measuring sensor is provided on the non-processed surface of the semiconductor wafer. is there.

The etching pot is formed in a container shape by disposing the semiconductor wafer as a bottom plate or a part of a side wall. However, the semiconductor wafer is arranged at a position where it is sufficiently immersed in the etching solution when the etching solution is put into the etching pot. Further, the semiconductor wafer is arranged so that its processed surface is exposed on the inner surface and can be directly contacted with the etching solution.

The etching head has a function necessary for advancing the etching process. That is, the etching head has a stirring means and a heating means for the etching liquid. Further, for example, when performing electrochemical stop etching, a power feeding means or the like can be provided in the etching head.

Further, a thickness measuring sensor is provided facing the outer surface (non-processed surface) of the semiconductor wafer arranged in the etching pot. As this thickness measuring sensor, a type that can measure the thickness of the object from one side is used. For example, there is a type that irradiates infrared rays or the like to measure the thickness in a non-contact state.

Further, the thickness measuring sensor is connected to the sensor moving device and is provided so as to be movable to an arbitrary position in the three-dimensional direction (XYZ direction). This sensor moving device is configured to adjust the optimum position of the thickness measuring sensor in the vertical direction, move the thickness measuring position, and the like.

Next, the function and effect of the present invention will be described.
An etching processing apparatus of the present invention uses the etching pot in which a semiconductor wafer to be processed is partially arranged, and has the thickness measuring sensor for measuring the thickness of the semiconductor wafer. The thickness measuring sensor can directly measure the thickness of the processed semiconductor wafer.

Therefore, during the etching process of the semiconductor wafer, it is possible to always grasp the thickness of the processed part which is melted and removed and becomes thinner. As a result, the etching process can be stopped at the timing when the thickness of the processed portion becomes the optimum thickness. Therefore, the thickness of the processed portion of the obtained semiconductor wafer can be finished with extremely high precision as compared with the conventional case of predictive control based on the etching rate.

Further, since the etching process can be stopped at the optimum timing in this manner, it is not necessary to measure the thickness of the semiconductor wafer before processing, which has been conventionally required. Further, it is not necessary to repeat the etching process for improving accuracy. Therefore, by using the etching processing apparatus of the present invention, the etching processing of the semiconductor wafer can be made highly accurate and highly productive. Furthermore, by using the measurement data of the thickness measurement sensor, it is possible to specify in advance the portion that may become an abnormal chip during etching processing.

As described above, according to the present invention, it is possible to provide an etching processing apparatus for a semiconductor wafer which can control the etching amount with high accuracy and can stop the etching processing at an optimum timing.

Next, as in the invention of claim 2, the etching processing apparatus causes the thickness measuring sensor to scan a predetermined range on the non-processed surface of the semiconductor wafer after the etching processing of the semiconductor wafer is started. It is preferable that one or two or more predetermined thickness measurement positions are specified, and then etching processing is performed while measuring the thickness at the thickness measurement positions.

In this case, by scanning the thickness measuring sensor, it is possible to grasp the processed shape being etched and to specify a predetermined thickness measuring position (for example, the center of the bottom of the recess). Therefore, it is not necessary to strictly control the setting direction when the semiconductor wafer is placed in the etching pot. Therefore, the etching work can be performed more efficiently.

Further, as in the invention of claim 3, the scanning range of the thickness measuring sensor is preferably a range of two or more chips among a plurality of chips obtained from the semiconductor wafer. That is, the semiconductor wafer is provided with a large number of recesses corresponding to the plurality of chips to be obtained. The thickness measuring sensor is scanned within two or more recesses, that is, two or more chips out of the large number of recesses. As a result, the thickness measurement position can be specified more accurately than in the case of scanning the area for one chip.

According to a fourth aspect of the present invention, the etching apparatus has a control unit that stores a desired product shape of the semiconductor wafer in advance, and the control unit has the thickness. It is preferable that the measurement shape of the semiconductor wafer is calculated using the measurement data during scanning of the measurement sensor, and the thickness measurement position is specified by comparing the processing shape with the product shape. In this case, the optimum thickness measurement position can be easily specified according to the desired product shape.

Further, as in the invention of claim 5, the etching processing apparatus stores a plurality of kinds of processing conditions in the control unit in advance, and one of the processing conditions is selected at the start of etching processing. Therefore, it is preferable that the desired etching process is automatically performed.

The above-mentioned processing conditions include, for example, basic conditions such as etching temperature and the like, as well as a thickness measurement position corresponding to a desired product shape, a target thickness and the like. Then, these conditions are stored for each product shape, for example. When starting the etching process, one condition is selected according to the desired product shape. Accordingly, the etching processing apparatus of the present invention,
In addition to temperature control of the etching solution, scanning by the thickness measurement sensor, identification of the thickness measurement position, and processing stop are automatically performed. In this case, since various product shapes can be easily dealt with, restrictions on the processing order and the like can be removed, and the productivity can be further improved.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the semiconductor wafer etching apparatus according to the embodiments of the present invention will be described with reference to FIGS. As shown in FIG. 1, the etching processing apparatus 1 of the present embodiment uses the semiconductor wafer 2 as a bottom plate, and an etching pot 4 configured by arranging the processed surface 28 of the semiconductor wafer 2 on the inner surface and the non-processed surface 29 on the outer surface thereof. have.

Further, the etching head 5 having the stirring means 51 and the heating means 52 for the etching liquid 8 placed in the etching pot 4, the thickness measuring sensor 6 arranged facing the non-processed surface 29 of the semiconductor wafer 2, and the thickness Sensor moving device 7 for moving the measuring sensor 6 to an arbitrary position in the three-dimensional direction
And have.

Then, the etching processing apparatus 1 performs the etching processing of the semiconductor wafer 2 from the non-processed surface 29 side of the semiconductor wafer 2 while measuring the thickness of the semiconductor wafer 2 with the thickness measuring sensor 6, The etching process is stopped when the predetermined thickness is reached. This will be described in detail below.

As shown in FIG. 1, the etching pot 4 is constructed by combining a ring-shaped pot base 41, a cylindrical body portion 42 combined thereabove and a semiconductor wafer 2 to be processed. The pot base 41 has a ring shape having a through hole 410 in the center. The semiconductor wafer 2 has a through hole 41 in the pot base 41.
It is arranged so as to close 0. A mask is previously attached to the semiconductor wafer 2 so as to cover the non-etched portion of the processed surface 29.

Above the pot base 41, as shown in FIG. 1, a tubular body 42 is assembled. The semiconductor wafer 2 is held between the body 42 and the pot base 41. At this time, a lip packing 425 is interposed between the semiconductor wafer 2 and the body portion 42 as a sealing material for preventing leakage of the etching solution 8.

As shown in FIG. 1, the pot base 41 and the body portion 42 are assembled by attaching the X-type packing 45 having an airway 450 penetrating vertically to the pot base 41 and the body portion 42.
And intervene between. Then, the groove base pockets 416 and 426 provided in the disposing portion of the X-type packing 45 in the pot base 41 and the body portion 42 are decompressed by a vacuum pump, so that the pot base 41 and the body portion 42 are drawn together. . As a result, the semiconductor wafer 2
The sealing property between the lip packing 425 and the lip packing 425 is kept good.

Further, as shown in FIG. 1, an etching head 5 is arranged above the etching pot 4. The etching head 5 is provided with a stirrer 51 as a stirring means and a heater 52 as a heating means in a downward direction from the main body 50. The stirrer 51 is connected to a rotary motor 511 provided above the main body 50, and is configured to appropriately rotate the stirring blade 512. Also, the heater 5
2 is connected to an external power source (not shown).

As shown in FIG. 1, the etching head 5 of the present example is provided with an electrode 53 for electrochemical stop etching. The electrode 53 is electrically connected to a power supply 531 for electrochemical stop etching via a lead wire 532. The power supply 531 is also connected to the semiconductor wafer 2 forming the etching pot 4 via a lead wire 533.

Further, as shown in FIG. 1, the etching head 5 has a water supply port 54 for supplying water for washing and an etching liquid supply port 5 for supplying the etching liquid 8.
5 is provided. An etching liquid drainage port 56 is provided on the opposite side of the water supply port 54 and the etching liquid supply port 55. A water supply means 548 for controlling the water supply operation is connected to the water supply port 54, and an etching solution supply means 559 for controlling the etching solution supply operation is connected to the etching solution supply port 55.

The etching pot 4 and the etching head 5 are mounted on a base 17 as shown in FIG. The base 17 has a cavity 170 inside and an opening 171 in the upper center portion. Base 17
A sensor moving device 7 for moving the thickness measuring sensor 6 to an arbitrary position in a three-dimensional direction is provided in the hollow portion 170.

The sensor moving device 7 has a transfer mechanism internally combining a servo motor and a ball screw,
The thickness measuring sensor 6 disposed on the upper portion is configured to move in the three-dimensional directions of up, down, left and right. Further, as shown in FIG. 1, the thickness measuring sensor 6 is arranged so as to project from the opening 171 of the base 17 and faces the non-processed surface 29 of the upper semiconductor wafer 2. The thickness measuring sensor 6 of this example is of a type that irradiates infrared rays to measure the thickness in a non-contact state.

The etching processing apparatus 1 also has a control unit (not shown) in which a desired product shape of the semiconductor wafer 2 is stored in advance. The control unit also stores in advance a plurality of types of processing conditions corresponding to a plurality of types of product shapes. Then, at the start of the etching process, a desired etching process is automatically performed by selecting one of the processing conditions.

The above processing conditions include the above product shape,
The scanning area of the thickness measuring sensor, the thickness measuring position, etc. are stored. These conditions can also be configured to be sent from the host production management computer to the control unit for storage. Further, the control unit calculates the processing shape of the semiconductor wafer 2 by using the measurement data when the thickness measuring sensor 6 is scanned, and compares the processing shape with the product shape stored in advance to specify the thickness measurement position. It is configured as follows. Further, the control unit is configured to control various functions provided in the etching head 5 according to the processing conditions.

Next, the procedure for etching the semiconductor wafer 2 using the present etching apparatus 1 will be described. First, a mask having a predetermined pattern is attached to the processed surface 28 of the semiconductor wafer 2. Next, as shown in FIG. 1, the semiconductor wafer 2 is placed on the pot base 41 to assemble the etching pot 4 having the above configuration.

Next, the etching head 5 is set on the etching pot 4 and placed on the base 17. Next, the processing conditions are selected by the control unit. As a result, the predetermined etching process is automatically started according to the instruction from the control unit.

First, the etching solution 8 adjusted to a predetermined temperature and concentration is injected into the etching pot 4 from the etching solution supply port 55 of the etching head 5. Further, during the etching process, the etchant 8 in the etching pot 4 is stirred by the stirrer 51 and the temperature of the solution is kept constant by the heater 52. As a result, the processed surface 28 of the semiconductor wafer 2 is gradually melted and removed at the portion without the mask, and the etching process proceeds.

Next, after the temperature of the etching liquid 8 is sufficiently stabilized and the etching process has progressed to some extent, the scanning by the thickness measuring sensor 6 is started. For example, the process is started about 5 minutes after the etching process is started. As shown in FIGS. 2 and 3, the measurement of the thickness by the thickness measuring sensor 6 is performed by irradiating infrared rays with the surface S of the non-processed surface 29 of the semiconductor wafer 2.
1 and the surface S2 of the processed surface 28 can be measured by measuring the interference of the reflected light. Therefore, the sensor moving device 7 first adjusts the vertical position of the thickness measuring sensor 6 to an optimum state.

Next, as shown in FIGS. 2 and 3, the XY driving device of the sensor moving device 7 is operated to cause the thickness measuring sensor 6 to scan in the plane, and the semiconductor wafer 2
Measure the thickness of. At this time, the scanning range of the thickness measuring sensor 6 is a quadrangle region having a side of 10 mm as shown in FIG. This is a range of four chips or more because the chip size to be obtained is 1.5 to 3.5 mm on a side.

From the thickness data obtained by the scanning of the thickness measuring sensor 6 as described above, the processing shape (pattern) of the semiconductor wafer 1 is grasped by the control unit. The control unit
The current processing shape is compared with the previously stored product shape to specify the thickness measurement position.

Specifically, as shown in FIG. 4, when the shape of the chip 20 to be obtained is a type having a concave portion 21 whose central portion is entirely depressed, the central portion K1 of the concave portion 21 is set at the thickness measuring position. Specify as. On the other hand, as shown in FIG. 5, when the shape of the chip 20 has a recess 21 in which an island-shaped bulge 215 is left in the center and is recessed around the bulge 215, the thickness of the recess K2 near the corner of the chip is measured. Specify as a position.

After the thickness measurement position is specified, the etching process proceeds while the thickness measurement sensor 6 constantly measures the thickness at that position. In this example, a mode is provided in which the actual etching rate is calculated from the thickness change for 30 seconds from the start of the thickness measurement, and then it is checked whether normal etching processing is performed.

Next, when the thickness of the semiconductor wafer 2 reaches a predetermined thickness, the etching process stop work is automatically started according to the instruction of the control unit. These work procedures are stored in the control unit in advance as the processing conditions.
Specifically, first, the heater 52 is stopped and the cleaning water 540 is introduced into the etching pot 4 through the water supply port 54. As a result, the etching solution 8 is diluted and cooled, and the etching reaction is stopped immediately.

The etching liquid 8 is sequentially overflowed and discharged as a waste liquid 89 from the drain port 56 by the supply of the cleaning water 540. The supply of cleaning water is continued for a certain period of time (for example, 3 minutes) from the time when the measurement value of the thickness measurement sensor 6 becomes constant, and the cleanliness of the processed surface 28 of the semiconductor wafer 2 is increased and then stopped.

Then, after stopping the rotation of the stirrer 51,
A mixed liquid of cleaning water and the etching liquid 8 is forcibly discharged from the etching pot 4 by a forced liquid discharging device (a vacuum liquid discharging device such as an ejector) not shown. Next, the etching pot 4 is disassembled, the semiconductor wafer 2 is taken out, and a series of etching processing is completed.

When performing the electrochemical stop etching, the switch 536 of the power source 531 is turned on when the heater 52 is stopped, and the semiconductor wafer 2 is energized. As a result, an oxide that is difficult to be etched is formed on the processed surface 28 by the anodic oxidation reaction, and etching is stopped.
Further, the switch 536 of the power supply 531 is turned off before the etching liquid 8 is forcibly discharged.

Thus, the etching processing apparatus 1 of this example
The etching process is performed by directly measuring the thickness of the semiconductor wafer 2. Therefore, the following various effects were obtained. That is, first, the thickness variation could be reduced to 1/3 or less of the thickness accuracy of the chip manufactured by the conventional etching processing apparatus. In addition, in the present example, the etching work which has conventionally been repeated several times (2 to 4 times) in thickness measurement and etching processing is
I was able to replace it with a single operation.

Further, conventionally, in order to deal with many kinds of products, it is necessary to deal with it by changing the etching condition for each product, which requires complicated process control. On the other hand, in the etching processing apparatus 1 of the present example, since the processing is automatically performed while directly measuring the thickness of the semiconductor wafer 2 as described above, it is possible to appropriately cope with all processing conditions. Therefore, with this one device, it is possible to deal with all kinds of products, and the process control can be greatly rationalized.

Further, in this example, the shape of the semiconductor wafer being etched can be directly grasped. Therefore, an accurate measurement position can be always maintained without being affected by the pattern shift of the front and back of the semiconductor wafer 2 and the shift of the set position. Therefore, the reliability of the etching process can be dramatically improved.

Further, in this example, since the minimum 4 chip portions are set as the scanning range of the thickness measuring sensor 6, when the tip portion being measured is abnormal, for example, an abnormality of the etching rate is detected and this is softened. Can also be automatically determined by. Therefore, a chip that may become abnormal can be specified in advance, and quality control afterwards can be made more reliable.

[0059]

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of an etching processing apparatus according to an embodiment.

FIG. 2 is an explanatory diagram showing a scanning state of the thickness measuring sensor in the embodiment.

FIG. 3 is an explanatory diagram showing a scanning region of a thickness measuring sensor in the embodiment.

FIG. 4 shows a chip shape according to an embodiment,
(A) Plan view, (b) DD sectional view taken on the line in the arrow.

FIG. 5 shows another chip shape in the embodiment,
(A) Plan view, (b) FF line arrow sectional view.

6A and 6B are a plan view and a sectional view taken along the line AA of the semiconductor wafer in the conventional example.

7A and 7B are a plan view and a cross-sectional view taken along the line BB of FIG.

FIG. 8 shows another chip shape in the conventional example,
(A) Plan view, (b) CC sectional view taken on the line in the arrow.

FIG. 9 is an explanatory diagram showing a configuration of an etching processing apparatus according to a conventional example.

FIG. 10 is an explanatory diagram showing the relationship between the etching time and the etching amount in the time management method according to the conventional example.

FIG. 11 is an explanatory diagram showing a relationship between a current value and an etching time in an electrochemical stop etching method according to a conventional example.

[Explanation of symbols]

1. ． ． Etching processing equipment, 2. ． ． Semiconductor wafer, 20. ． ． Chip, 21. ． ． Recess, 3. ． ． mask, 4. ． ． Etching pot, 5. ． ． Etching head, 6. ． ． Thickness measurement sensor, 7. ． ． Sensor moving device, 8. ． ． Etching solution,

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-4-91434 (JP, A) JP-A-1-165184 (JP, A) JP-A-5-283394 (JP, A) JP-A-6- 13294 (JP, A) JP-A-3-171728 (JP, A) JP-A-1-232731 (JP, A) JP-A-7-111258 (JP, A) Actually developed 59-70336 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 21/306 H01L 21/3063 H01L 21/308

Claims (5)

(57) [Claims] 1. An etching pot configured by using a semiconductor wafer as a bottom plate or a part of a side wall and arranging a processed surface of the semiconductor wafer as an inner surface and a non-processed surface as an outer surface, and an etching pot put in the etching pot. An etching head having a liquid stirring means and a heating means, a thickness measuring sensor arranged facing the non-processed surface of the semiconductor wafer, and a sensor moving device for moving the thickness measuring sensor to an arbitrary position in a three-dimensional direction. And, the etching processing of the semiconductor wafer is performed while measuring the thickness of the semiconductor wafer from the non-processed surface side of the semiconductor wafer by the thickness measuring sensor, and the thickness of the semiconductor wafer becomes a predetermined thickness. An etching processing apparatus for a semiconductor wafer, characterized in that the etching processing is configured to be stopped when it reaches. 2. The etching processing apparatus according to claim 1, wherein after the etching processing of the semiconductor wafer is started, the thickness measuring sensor scans a predetermined range on a non-processed surface of the semiconductor wafer to obtain one or more. Is configured to specify a predetermined thickness measurement position and then perform etching processing while measuring the thickness at the thickness measurement position. 3. The etching processing apparatus for a semiconductor wafer according to claim 2, wherein the scanning range of the thickness measuring sensor is a range of two or more chips among a plurality of chips obtained from the semiconductor wafer. 4. The etching processing apparatus according to claim 2 or 3, further comprising a control unit that stores a desired product shape of the semiconductor wafer in advance, and the control unit includes:
When the thickness measurement sensor is scanned, the processing shape of the semiconductor wafer is calculated using the measurement data, and the thickness measurement position is specified by comparing the processing shape with the product shape. Characteristic semiconductor wafer etching equipment. 5. The etching processing apparatus according to claim 4, wherein a plurality of types of processing conditions are stored in advance in the control unit, and one of the processing conditions is selected at the time of starting the etching process to obtain a desired processing condition. An etching processing apparatus for a semiconductor wafer, which is configured to automatically perform etching processing.