JPS63261843A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To mark defective elements on a semiconductor wafer without introducing foreign matters to be generated thereby and to make it possible to provide marks having a uniform size and easy to recognize, by checking characteristics of a multiplicity of elements as formed on a semiconductor wafer, before etching the surface of any defective element for marking the same. CONSTITUTION:A multiplicity of elements are formed on a semiconductor wafer 6, and a first positive-type photoresist 8 is applied on the surface of the wafer 6 except a region where a measuring electrode is provided. After checking characteristics of the elements, parts of the first photoresist 8 located on the surface of defective elements are exposed so that windows are opened in those parts. Second photoresist 9 is applied on the windows of the first photoresist 8 located on the measuring electrode. Then, the surface of each defective element not covered with the first or second photoresist 8, 9 is etched so that such element is broken. When the first and second photoresists 8 and 9 are removed, the surface of the defective element is marked by a window 7a opened in an insulation film 7 on the defective element. In this manner, any defective element can be marked and discriminated reliably, not dependent on its dimensional difference.

Description

[Detailed Description of the Invention] The present invention relates to a method for manufacturing a semiconductor device, and more specifically, a method for manufacturing a semiconductor device, in which a large number of elements are formed on a semiconductor wafer, and after checking their characteristics,
The present invention relates to a method for marking defective elements.

Conventionally, in the manufacturing process of semiconductor devices such as ICs, a large number of elements (2) (2) are placed on a semiconductor wafer (1), as shown in FIG.
)... is formed, first each element (
2) Check the characteristics of (2)... and find the defective element (2a
)... mark. Each of the above elements (2) (2)
When checking the characteristics of..., as shown in Figure 8, after forming an insulating film (3) on the entire surface of the semiconductor wafer (1) to protect the element surface, Open the window, and this window brightness is from the part (3a) to the gauge (4).
Check the characteristics by touching the measuring electrode. and,
After checking, if a defective element (2a) is found, the surface of the element is marked with a marker (5). The above marking can be done by dropping ink onto the surface of the defective element using a marker (5), by making scratches on the surface of the defective element using a diamond needle or piano wire as a marker (5), or by using a laser light source as a marker (5). The melting point is marked on the surface of the defective element.

In recent years, the degree of integration of semiconductor devices has increased and the element dimensions have become smaller. After forming and checking its characteristics, when marking the defective element (2a), first drop ink on the surface of the defective element and mark it, the ink will scatter around the area and the ink will adhere to the non-defective element, which will determine it as defective. In addition, the characteristics may change due to ink adhesion even if it is not determined to be defective.Furthermore, if the defective elements are not continuous and the ink drips discontinuously, the viscosity of the ink increases and marking 6. If the surface of a defective element is marked with flaw points, the flaw points may not be visible depending on the angle, and as the element size becomes smaller, the flaws themselves may become difficult to form. Furthermore, when a laser beam is used to make a melting point on the surface of a defective element, dust may be generated and scattered around the device, resulting in poor appearance and poor characteristics, and laser equipment is expensive.

The present invention is designed to form a large number of devices on a semiconductor wafer, check the characteristics of each device in the wafer state, and mark defective devices. After coating the first photoresist and checking the characteristics of each element, there is a step of partially exposing the first photoresist on the surface of the defective element, and after opening the exposed area of the first photoresist, the measurement electrode is removed. The first photoresist window coating of the portion includes the steps of applying a second photoresist to the portion and marking the surface by etching defective elements not covered with the first and second photoresists. Features.

A large number of elements are formed on a Muzato semiconductor wafer, and the measurement electrode part is removed (after coating the wafer surface with a positive type first photoresist and checking the characteristics of each element, the first photoresist on the surface of the defective element is exposed and a window is opened). After that, a second photoresist is applied to the first photoresist window of the measurement electrode portion, and the surface of the defective element that is not covered with the first and second photoresists is further etched, resulting in destruction of the element. .

5 Points In the figures, (6
) is a semiconductor wafer on which many elements are formed, (7
) is formed on the semiconductor wafer (6) and protects the surface of each element with 5i02, an insulating film such as SiN, (8) is the positive type first photoresist coated on the insulating FJ (7), (9) 1 is a second photoresist coated on the first photoresist (8), (10) is a probe for checking the characteristics of the above-mentioned element, and (11) is an optical fiber for exposure.

The operation of the present invention based on the above configuration will be described below.

First, as shown in FIG. 1, when a large number of elements are formed on a semiconductor wafer (6), an insulating film (7) is formed on the surface of the semiconductor wafer (7) to protect the elements. 1 Apply photoresist (8) to open a window in the measurement electrode portion on the surface of each element.Next, as shown in FIG. After removing the insulating film (7) of (8a), as shown in FIG. 3, the probe (10) is brought into contact with the element measurement electrode from the window part (8a) to check the characteristics. As a result of the characteristic check, as shown in FIG. 3, the first photoresist (8) on the surface of the defective element is exposed to light through the optical fiber (11) through the shield tube (12).

Then, since the first photoresist (8) is positive type, when developed, the exposed part of the first photoresist (8) is removed and a window portion (8b) is formed as shown in FIG. , the surface of the defective element is exposed 6 Next, after applying a negative or positive second photoresist (9) on the first photoresist (8), as shown in FIG. The second electrode is uniformly applied to each element, excluding the measurement electrode part.
When the photoresist (9) is opened, the window of the first photoresist (8) corresponding to the measurement electrode is exposed at a portion (8b).
) is coated with a second photoresist (9). and,
When the surface of each element is uniformly etched using the second photoresist (9) as a mask, the surface of the good element is covered with the first photoresist (8) (not shown), and the surface of the defective element is covered with the first photoresist (8). Because it is not covered by (8),
The surface of the defective element is etched through the insulating film (7) to the element region, and the defective element is destroyed. After that, as shown in FIG. 6, when the first and second photoresists (8) and (9) are removed, the window brightness of the insulating film (7) on the surface of the defective element is reduced to part (7).
a) remains and is marked.

According to the present invention, after forming a large number of devices on a semiconductor wafer and checking the characteristics of each device in the wafer state, the surface of the defective device is marked by etching, which prevents the generation of foreign matter due to the marking. Moreover, the mark size is uniform and easy to recognize. Moreover, the marking etches into the element area of the defective element and destroys the element, which prevents the contamination of unreliable elements and reduces the element size. It is possible to reliably distinguish between good and bad markings without depending on the marking.

[Brief explanation of drawings]

FIGS. 1 to 6 are cross-sectional views illustrating the method of manufacturing a semiconductor device according to the present invention in the order of steps. FIG. 7 is a plan view of a semiconductor wafer on which elements are formed, and FIG. 8 is a sectional view showing a conventional method for checking characteristics of elements formed on a semiconductor wafer and marking defective elements. (6)...Semiconductor, -c, (8)...First photoresist, (8b)...First photoresist window is a portion. (9)...Second photoresist.

Claims (1)

[Claims] (1) When forming a large number of devices on a semiconductor wafer, checking the characteristics of each device in the wafer state, and marking defective devices, a positive type first photoresist is applied to the wafer surface excluding the measurement electrode portion on the surface of each device. After checking the characteristics of each element, there is a step of partially exposing the first photoresist on the surface of the defective element, and after opening the first photoresist exposed area, opening the first photoresist window on the measurement electrode part. A method for manufacturing a semiconductor device, comprising the steps of: applying a second photoresist to a portion; and etching and marking a defective element not covered with the first and second photoresists on the surface.