JPS58123730A - Semiconductor wafer etching device - Google Patents

Abstract

PURPOSE:To perform the etching uniformly and in high degree of accuracy by a method wherein a temperature controller for etching liquid and a bubble generator, with which bubbles are generated in the etching liquid, are provided. CONSTITUTION:The etching liquid of the prescribed quantity is filled in a vessel 3, and the prescribed temperature is set by a temperature controller 7. The prescribed number of semiconductor wafers 11 are supported by a supporting part 9a in the state of condition wherein a great number of bubbles, generated by a bubble generator 8, are existing in the etching liquid, and an etching work is performed. Then, after said etching work has been finished, a pinching frame 9b is moved to a cleaning vessel 4 using an electric controller 10, and a cleaning work is performed there. In synchronizing with the above, the temperature inside an etching vessel 3 is set at the prescribed value by adjusting a thermostat 7a. Subsequently, new semiconductor wafer 11 is placed on the supporting part 9a, and a desired etching process is performed by repeating the above operation in the same manner.

Description

[Detailed description of the invention] Technical field of invention The present invention relates to a semiconductor wafer etching apparatus.

Technical background of the invention and its problems Conventionally, semiconductor wafer etching equipment has either dipped the semiconductor wafer in an etching solution and performed the etching process without rotating it with a rotor, or directly etched the semiconductor wafer up and down. The structure is such that it can be moved and swung while being subjected to machining and chiming processes. However, in a semiconductor wafer etching apparatus having such a structure, the degree of etching depends on the shape of the jig that supports the semiconductor wafer, making it difficult to perform uniform etching.

When etching a semiconductor wafer K of 10 μm or more to 41, this drawback becomes noticeable. Also,
A semiconductor wafer etching apparatus has been developed in which a mist of etching solution is sprayed onto the semiconductor wafer. In this semiconductor wafer etching equipment,
Although the etching process can be carried out with an extremely uniform degree, it is difficult to recover the etching solution, and has the drawbacks of poor economic efficiency and low mass production.

OBJECTS OF THE INVENTION An object of the present invention is to provide a semiconductor wafer etching apparatus which can perform extremely uniform etching with high accuracy and can easily control the amount of etching.

Overview of Mima The present invention relates to an etching solution temperature controller and process.

This semiconductor wafer etching apparatus is equipped with a bubble generator that generates bubbles in the tinting liquid, so that uniform etching can be performed with high precision, and the amount of etching can be easily controlled.

Embodiment of the Invention FIG. 1 is an explanatory diagram showing a schematic configuration of an embodiment of the invention. 1 in the figure is the main body of the etching apparatus. The etching apparatus main body 1 is partitioned into an etching tank 3 and a cleaning tank 4 via a partition plate 2. Below the cleaning tank 4, a cleaning water supply pipe 5& and a cleaning water discharge pipe 5k are provided, penetrating the bottom of the etching apparatus main body 1. An etching liquid supply pipe 6& and an etching liquid return pipe 6b are provided below the etching tank 3 by inserting them into the bottom metal fittings of the etching apparatus main body 1. The etching liquid supply pipe 6a and the etching liquid return pipe 6b are connected to an etching liquid temperature control device 1 having a built-in constant temperature setting mechanism RA including a cooler, a heat exchanger, an etching liquid return motor, an etching liquid temperature sensor, etc. ing. At the bottom of the etching tank 3, a bubble generator I is installed. As shown in FIG. 2, the bubble generator 8 generates bubbles 11 from the outside of the etching apparatus body 1 into the side of a bubble generating box #a made of acid-resistant synthetic resin and having an open top. It has a structure in which the holder is fixed with a presser plate 8@. The lid 8d and the presser plate 8 are made of a fluorine-based resin that is not corroded by the etching solution.The foaming hole 8c releases the bubble-generating gas supplied from the bubble-generating gas supply w8b into the etching solution. It is preferable to set the diameter to about 200 pln or less, as it may cause foaming in some cases.In addition, the size of the lid 8d is determined by the size of the semiconductor wafer to be etched (described later). It is preferable to set the appropriate setting according to the diameter of the semiconductor urchin and the number of sheets to be processed.For example, when the diameter of the semiconductor sea urchin is 2 to 4 inches and the number of sheets to be processed is 50 to 100, the lid ad (Q length is 80 to 100 ■, side 2
It is desirable to set it to 50-300■.

9. Inside the etching bath a, a drive unit SO semiconductor industry/holding unit 9a including a drive motor and drive control equipment is housed so as to be freely accessible and removable. The drive unit 9 is electrically connected to the drive unit 9, a clamping frame 9b that clamps the semiconductor wafer holding unit 9a-, an arm guide 9 from which the clamping frame #b is suspended via a and Gq the holding frame #b to 7-mugai 1.
It is composed of an electric control section 10 that allows movement. In this electric control section 1#, the etching liquid temperature and drive mode are electrically set and controlled. In addition, the arm guide g4 is manufactured by engineering.

An etching tank 3 and a cleaning tank 4 are installed above the etching device main body 1.
It is formed to straddle the . In addition, the semiconductor wafer holding portion 9a has a plurality of grooves formed at predetermined intervals on the inner surface of the opposing holding plate 9a1 to hold the peripheral edge portions of the semiconductor wafers 1-11, which are workpieces and chipped bodies. It is designed to hold 11 to 50 to 100 semiconductor urchins. The electric control unit 10 is electrically connected to the constant temperature setting mechanism 11 of the etching liquid temperature control device 1, and controls the constant temperature setting mechanism 1a in conjunction with the movement of the holding frame Jk, thereby controlling the etching liquid in the etching tank 3. temperature is set to a predetermined temperature.

Etching liquid is supplied into the etching tank 3 from the etching liquid supply pipe 6a, and the etching liquid that has flowed out is recovered through the etching liquid return pipe 6b.
A certain amount of etching solution is always filled. In addition, washing water is supplied into the washing tank 4 from a washing water supply pipe 5a, and by collecting the washing water that flows out from the washing water discharge pipe 5b, a certain amount of washing water is always filled. It is set as K. Furthermore, inside the cleaning tank 4, a rotor for rotating the etched semiconductor wafer 11 and a bubble cape are provided to remove the acid attached to the surface of the semiconductor wafer 11 during the etching process. It may also be promoted.

According to the semiconductor etcher LA constructed in this manner, the temperature of the etching solution is set to a predetermined temperature by the etching solution temperature control device 1. , and with a large number of bubbles generated in the etching solution by the bubble generator 1, a predetermined number of semiconductor wafers 11 are held in the semiconductor wafer holder pm and immersed in the etching bath 3. Then, after the etching process, the electric control unit 10 transfers the holding frame #b to the cleaning tank 4 and cleans the semiconductor wafer 11. At the same time, the electric control unit 10C) Based on this, the constant temperature setting mechanism 7a is adjusted to set the temperature inside the heating tank 3 to a predetermined temperature. After that, the holding part 9
A new semiconductor wafer 11 is placed on top of a, and the same operation is repeated to apply the desired finishing and tinting treatment to the substrate wafer 11. As a result, the following effects are achieved.

■ The variation in the amount of etching can be set to ±1 μm for the thickness of the semiconductor layer 11.

(With the conventional device, the variation was ±5μmO.) ■ The parallelism without machining and ching is shown in curve (1) in Figure 4.
As shown in FIG. 2, the difference in thickness of the semiconductor wafer 11 (D) can be reduced to one-fifth to one-sixth of that of the conventional device shown by the curve ω) in the figure.

- The specularity of the finished surface after etching is much closer to the specularity of mechanically polished products than when using conventional equipment, and the life of the etching solution is approximately 1.5 times longer.

■ Semiconductor wafer holding section 9 that holds semiconductor wafer 11
Since the amount of etching is not affected by the shape of a, ready-made carriers can be used for semiconductors 8-, & 9. ni□11111
□fbjhka8□4゜■ It is possible to improve productivity by shortening the processing time required for one-time machining and tinkering.

As described in detail, the semiconductor wafer etching apparatus of the present invention can perform extremely uniform etching with high accuracy, and the amount of etching can be easily controlled, which is a remarkable effect. is also O.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the schematic configuration of an embodiment of the present invention;
Fig. 2 is a diagram of the bubble generator, Fig. 3 is a perspective view of the lid O of the bubble generator, and Fig. 4 is a diagram showing the difference in wall thickness at the center of the semiconductor wafer and the difference in thickness from the outer periphery. FIG. 3 is a characteristic diagram showing the relationship between distances. , 1...work, cinder device main body, 2--partition plate, 3...
- Engineering, etching tank, 4... Cleaning tank, j6 - Washing water supply pipe, sb... Washing water discharge pipe, ga... Engineering, Chinda liquid supply pipe, 6b... Etching liquid return pipe, 1... Etching liquid temperature control device, 7 m... Constant temperature setting mechanism,
8...Bubble generator, 8a...Bubble generating box, 8b...
・Bubble-generating gas supply pipe, Je... foaming hole, am...
Lid body, 8...pressing plate, 9...driver, ta...
Semiconductor wafer holding part, 9b... Holding part, C... Hook, 9d... Arm guide, 10... Electrical control part, 11... Semiconductor que/\, L"... Semiconductor wafer・-Etching device.

Claims (1)

[Claims] A bubble generator provided in the etching tank is connected to the etching tank via a tinda liquid supply pipe and a tinda liquid return pipe, and a constant temperature setting mechanism is provided. It has a built-in temperature controller and a holding part for the object to be etched, and the holding part is used for the above-mentioned process. 4. A semiconductor wafer etching apparatus which is equipped with a drive unit for moving the etching body into and out of the etching bath, a nine-workpiece, and a etching body holding mechanism.