JPS6235642A - Manufacture of semiconductor element - Google Patents

Abstract

PURPOSE:To produce within a short period of time a semiconductor element equipped with a desired area and mesa geometry by a method wherein a mesa groove is provided in one side or both sides of a semiconductor wafer before it is segmented into elements along the mesa groove. CONSTITUTION:A semiconductor wafer 1 coated with resist film 2 is placed in a mixed acid. The acid attacks the semiconductor wafer 1, whereby a mesa groove 6 is formed due to the etching effect. In the same process, a through connection is established between a groove 7 shaped after a linear pattern 5 and a groove 8 originating in a dicing groove 3 for the separation of a semiconductor section 11 outside the linear pattern 5, also due to the etching effect. After the separation, etching is stopped. Dicing or bending along the mesa groove 6 results in the segmentation of the semiconductor wafer 1 for the production of a semiconductor element. This method ensures uniform depth for a mesa groove by short-period application of etching for the realization of a semiconductor element equipped with a desired area and mesa geometry.

Description

[Detailed description of the invention] [Technical field to which the invention pertains]

The present invention relates to a method for manufacturing a semiconductor device, in which a mesa groove is formed on one or both sides of a semiconductor board, and then the semiconductor board is divided at the mesa groove portion by dicing or the like to form device pieces.

[Prior art and its problems]

A method for forming mesa grooves on a semiconductor board is to use a mixed acid such as hydrofluoric acid, nitric acid, and acetic acid as an etching solution, and then protect the surface of the semiconductor board with a resin film or the like, exposing only the mesa groove formation area. A method of etching by dipping and shaking is often used. However, in this case, the etching conditions, ie, the number of semiconductor boards, the pattern of the mesa grooves, the composition or temperature of the etching solution, and the amount of the etching solution. The etching speed changes not only when the rocking methods are clearly different, but also due to minute differences or variations in them, and the depth of the mesa groove formed often differs even if etching is performed for the same time. If the groove depths differ, there will be differences in the mesa groove shape or area of each element piece, making it impossible to obtain desired characteristics. Therefore, in order to prevent the mesa groove from becoming too deep, the etching process is stopped midway, the groove depth created by etching is measured, and the etching process is repeated several times to reach the target mesa groove depth. I had no choice but to take the method of obtaining . Therefore, in order to always obtain a uniform mesa groove depth, there is a drawback that it takes a very long time to form the mesa groove.

[Purpose of the invention]

The present invention eliminates the above-mentioned drawbacks and provides a method for measuring etching depth.
To provide a method for manufacturing a semiconductor device, capable of always forming a uniform mesa groove depth through short-time etching operations without repeating re-etching, and obtaining a device piece having a desired area and mesa shape. With the goal.

[Key points of the invention]

According to the present invention, a linear groove having a predetermined depth from the back surface of the semiconductor board and reaching from the periphery of the semiconductor board to the periphery is formed at the edge of the semiconductor board by machining, and a mesa groove is formed by etching from the surface. When performing the formation, etching is also performed from the linear surface portion facing the linear groove, and the etching is stopped when the linear portion penetrates through the etching and the edge of the semiconductor board is separated. objectives are achieved.

[Embodiments of the invention]

Figure 1 181. Q) 1 and 2 show one embodiment of the present invention. As shown in FIG. 1 (al), the lower surface of the semiconductor board 1 is covered with a resist 2, and a groove 3 of length 1 x t is formed by dicing.Next A resist 2 having a linear exposed pattern 4 similar to conventional mesa groove formation is applied on the upper surface.
A linear exposed pattern 5 is also formed on the upper surface side facing the dicing groove 3. This straight line pattern 5 and its lower part 1
113 is provided at the edge of the semiconductor board as shown in FIG. When the semiconductor board 1 coated with the resist is immersed in a mixed acid, an etched mesa groove 6 is formed as shown in FIG. The grooves 8 formed by the progress of etching are connected, and the semiconductor plate portions 11 outside the linear pattern 5 are separated. The operator recognizes this separation and stops etching. Thereafter, the semiconductor board 1 is separated at the mesa groove 6 by dicing or bending to obtain element pieces. Since the linear patterns 5 and the dicing grooves 3 are provided in the margins of the semiconductor board, they do not affect the number of element pieces that can be removed.During etching, etching also proceeds from the dicing grooves 3 as described above. If the relationship between the depth of the mesa groove 6 formed before the edge 11 of the semiconductor board is separated and the depth t of the dicing 1l13 is investigated in advance and a diagram as shown in FIG. 3 is obtained, the dicing groove depth can be determined. By setting t, it is possible to always form the mesa groove 6 with a desired depth. FIG. 4 (al, (bl) shows another example, in which both mesa-shaped elements are manufactured. As shown in FIG. 4 fal, dicing grooves 3 are formed in advance, and the resist 2 is An exposed pattern 51 is also provided in the exposed portion of the dicing groove 3. As shown in Fig. 4), the etching groove 7 from the top surface and the etching groove 8 extending from the dicing groove 3 are connected to each other to form a pattern on the semiconductor substrate. The edges 11 are separated, thereby determining the end of the etching and making it possible to form mesa grooves 6 of uniform depth from both sides.

【Effect of the invention】

According to the present invention, when forming a mesa groove on a semiconductor board by etching, a linear groove reaching from the periphery of the semiconductor board to the periphery is formed in advance from the back side, and the etching groove from the front side advances from the linear groove. By determining the final stage of etching by connecting with the etched groove, there is no need to interrupt etching or repeatedly measure the etching depth, and the mesa groove formation time can be significantly shortened. Even if the etching conditions are different, a mesa groove of a predetermined depth can always be formed, which is extremely effective for manufacturing semiconductor elements with uniform characteristics.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the process of forming a mesa groove in an embodiment of the present invention, FIG. 2 is a plan view corresponding to FIG. 1 181,
FIG. 3 is a relationship diagram between the depth of the mesa groove to be formed and the depth of the dicing groove, and FIG. 4 is a sectional view showing the process of forming the mesa groove in a different embodiment. 1: semiconductor board, 2: resist, 3: dicing groove, 4.
5: exposed pattern, 11: semiconductor board separation part. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1) In a method in which a mesa groove is formed by etching from the surface of a semiconductor board and then the semiconductor board is divided at the mesa groove to obtain element pieces, the edge of the semiconductor board has a predetermined depth from the back surface of the semiconductor board. , a linear groove reaching from the periphery to the periphery of the semiconductor board is formed by machining, and during etching to form a mesa groove, etching is simultaneously performed from the linear surface portion opposite to the linear groove, and the linear portion is formed by etching. A method for manufacturing a semiconductor device, characterized in that etching is stopped when the etching is penetrated and the edge of the semiconductor board is separated.