JPH02305441A - Wafer - Google Patents

Abstract

PURPOSE:To prevent the diffusion of particles due to the diffusion of a cleaning residue from the end part of a wafer into a chip formation region by a method wherein at least one round of annular SiO2 film to rise from the surface of the bulk Si part of the wafer is provided on the periphery, which encircles the chip formation region, of the wafer. CONSTITUTION:At least one round of annular SiO2 film 7 to rise from the surface of a bulk Si part 3 of a wafer 1 is provided on the periphery, which encircles a chip formation region 5, of the wafer 1. In the wafer constituted in such a way, a cleaning residue to remain between a basket 4 for housing the wafer 1 and the peripheral edge of the wafer 1 is stopped by the film 7 and is prevented from diffusing into the region 5 at the time of a drying process to be performed after the wafer 1 is housed and cleaned in the basket 4. Thereby, particles being contained in a cleaning fluid or particles being adhered on the basket 4 are prevented from diffusing into the region 5.

Description

[Detailed Description of the Invention] [Summary] With respect to a wafer on which semiconductor chips are formed, the chip forming area is removed for the purpose of preventing the diffusion of particles due to the diffusion of cleaning residual liquid from the wafer edge into the chip forming area. An annular 5i02 groove that protrudes from the bulk Si surface of the wafer is provided at least once around the surrounding wafer.

[Industrial Field of Application] This invention relates to a wafer on which semiconductor chips are formed.

In recent years, the patterns drawn on wafers during the manufacturing process of highly integrated semiconductor devices have become increasingly finer.
As a result, even if fine particles, which have not been a problem in the past, adhere to the wafer during cleaning, it becomes a cause of deterioration in the yield and reliability of semiconductor devices formed from the wafer.

[Prior Art] Conventionally, in the manufacturing process of MOS transistors, prior to the gate oxide film formation process, bulk S! 5i02 on top
The LOGO8 process in which 111 is formed is performed, and the 5th
i02! ! After the 3i3N411 is formed, the 3i3N411 is removed, and the bulk Si3 is exposed between the 3i02 films 2 formed in a raised state on the surface of the wafer 1, as shown in FIG. A large number of such wafers 1 are housed in a basket 4 made of quartz as shown in FIG. 4, and after being cleaned and dried, they are sent to the next process.

[Problem to be Solved by the Invention] The wafer 1 formed by the above process has a chip forming area 15 in which a large number of chips are formed in the center of the wafer 1, as shown by the chain line in FIG. , 5i0212 is formed in a predetermined pattern in the chip forming region.

Bulk Si3 is exposed around the chip forming region 5, and bulk Si3 is also exposed in the scribe line between each chip.

5i021!2 is water repellent and bulk S13
has hydrophilic properties.

When such a wafer 1 is housed in the basket 4 and cleaned in the above process, cleaning liquid tends to remain in the gap between the wafer holding piece 6 formed on the inner peripheral surface of the basket 4 and the edge surface of the wafer 1, and the cleaning liquid tends to A scribe line extending in the form of a groove from the edge of the wafer 1 to the center of the wafer 1 rises due to capillary action, and particles contained in the cleaning liquid and particles attached to the basket 4 are deposited in the chip forming area as shown in FIG. 4, for example. It spreads within the range shown by the broken line. Therefore, the polygon of the chip within this range is reduced.

Therefore, in order to prevent such problems, cleaning is carried out while constantly purifying the cleaning liquid using a purifying device, but a sufficient effect cannot be expected.

SUMMARY OF THE INVENTION An object of the present invention is to provide a wafer that can prevent the diffusion of particles due to the diffusion of cleaning residual liquid from the wafer edge into the chip forming region during the wafer drying process.

[Means for Solving the Problems] FIG. 1 is a diagram illustrating the principle of the present invention. That is, the annular 5i02 film 7 that protrudes from the bulk Si3 surface of the wafer 1 is provided at least once around the wafer 1 surrounding the chip forming region 5. The cleaning residual liquid remaining between the basket and the periphery of the wafer is Si0
2gt7 to prevent diffusion into the chip forming region 5.

[Example] An example embodying the present invention will be described below with reference to FIG. Note that the same components as those in the conventional example will be described with the same numbers.

5i02! around the chip forming area 5 of the wafer 1. l!
7 is formed in a ring shape. This 5i02!17 is LO
3i02pII! in the chip formation area 5 in the CO8 process! In the process of forming wafer 2, 3i3N4m is removed in a predetermined pattern in chip forming area 5, and at the same time, 5i3N411J around chip forming area 5 is oxidized in a state in which 5i3N411J is removed in a ring shape. At the same time as the 5i02 film 2 shown in FIG.
i1jl! A 3i02 film 7 is formed around 5.

Then, the 5i3N41 etc. were removed to expose the bulk Si3 in a predetermined pattern, and the 51N41 shown in FIG.
Similar to the 02 film 2, the 5i02 film 7 is formed in a raised state from the surface of the bulk Si3. Also, this 5i02
The membrane 7 is formed at a position passing inside the wafer holding piece 6 with the wafer 1 housed in the basket 4.

Now, in the wafer 1 configured in this way, the basket 4
In the drying process after cleaning and accommodating the wafer, the wafer holding piece 6
Even if the cleaning liquid remains on the central part of the wafer 1
5102 membrane 7 prevents the cleaning liquid from spreading along the scribe line due to capillary action. Therefore, fc? Since particles contained in the liquid or particles attached to the basket 4 are prevented from diffusing into the depth forming region 5, the yield and reliability of a large number of chips formed from this wafer 1 are improved. can be done.

In addition, in the above example, the annular 5i02! l! Although 5i02 film 7 was formed only once around the chip forming area 5, it is possible to more reliably prevent particle diffusion by forming this film multiple times. It can also be formed by annularly exposing and removing Si, and then oxidizing the exposed bulk Si.

[Effects of the Invention] As described in detail above, the present invention exhibits an excellent effect of preventing the diffusion of particles due to the diffusion of cleaning residual liquid from the edge of the wafer to the center in the wafer drying process.

[Brief explanation of the drawing]

Fig. 1 is a diagram explaining the principle of the present invention, Fig. 2 is a front view showing a state in which a wafer according to an embodiment embodying the present invention is housed in a basket, and Fig. 3 is a diagram illustrating the state in which an oxide film is formed in the chip forming area. FIG. 4 is a cross-sectional view showing the wafer in a state in which the wafer is dried. FIG. 4 is a front view showing the conventional wafer drying process. In the figure, 1 is a wafer, 3 is a bulk 511, 5 is a chip forming region, and 7 is a 5i02 film. Figure 1: Explanation of the principle of the present invention Figure 3: Figure 4

Claims (1)

[Claims] 1. A wafer surrounding a chip forming region (5) (a wafer characterized in that at least one circumference of the wafer (1) is provided with an annular SiO_2 film (7) that rises from the bulk Si (3) surface of the wafer (1)) .