JPH0462553A - photomask - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a technology for manufacturing semiconductor devices, and particularly to a technology that is effective when applied to photomasks used in photolithography technology.

[Conventional technique] Conventionally, before performing ion implantation on a semiconductor wafer,
Alternatively, using a stepper with a reticle having an ion implantation pattern for two chips, all the semiconductor chips are sequentially exposed to the integrated circuit forming portion of the positive photoresist deposited on the semiconductor wafer, and then a peripheral edge exposure device is used before development. It was used to expose positive photoresist on the periphery of semiconductor wafers. Thereafter, development was performed to form a desired resist pattern and to remove the positive photoresist at the peripheral edge of the semiconductor wafer.

[Problems to be Solved by the Invention] However, when an ion implantation pattern is formed using a stepper using a reticle, the exposure process for forming the ion implantation pattern and the exposure process for removing the photoresist from the periphery of the semiconductor wafer are difficult. Since development cannot be performed without passing through two steps, there is a problem in that throughput cannot be improved and costs cannot be reduced.

Furthermore, in order to expose the peripheral edge of the semiconductor wafer, a peripheral edge exposure device must be used, which requires equipment in addition to the stepper, and there is a problem in that costs cannot be reduced.

Therefore, the main purpose of the present invention is to
It is an object of the present invention to provide a photomask that allows exposure of the peripheral portion of a semiconductor wafer to be performed simultaneously or consecutively with the exposure process of the integrated circuit forming portion.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

Means for Solving the Problems] Representative inventions disclosed in the present application will be summarized as follows.

The invention according to claim 1 is a photomask compatible with a positive photoresist used in a same-magnification exposure apparatus, the photomask having a wafer peripheral section corresponding to a peripheral portion of a semiconductor wafer and an integrated circuit forming section corresponding to an integrated circuit forming portion of the semiconductor wafer. The pattern includes a circuit forming section and a non-integrated circuit section outside the integrated circuit forming section and inside the wafer peripheral section, and at least the wafer peripheral section serves as a light-transmitting area and the non-integrated circuit section is outside the integrated circuit forming section and inside the wafer peripheral section. The sections are configured as light-shielding areas.

The invention according to claim 2 is a photomask compatible with a negative photoresist used in a same-magnification exposure apparatus, which includes a wafer peripheral section corresponding to a peripheral portion of a semiconductor wafer, and an integrated circuit corresponding to an integrated circuit forming portion of the semiconductor wafer. The pattern includes a circuit forming section and a non-integrated circuit section outside the integrated circuit forming section and inside the wafer peripheral section, wherein at least the wafer peripheral section serves as a light-shielding area and the non-integrated circuit section is configured as a light-transmitting area.

According to a third aspect of the present invention, in the photomask according to the first or second aspect, a predetermined pattern is formed in the integrated circuit forming section.

[Operation] When using the photomask according to the present invention in which a pattern to be transferred is formed in the integrated circuit formation section among the photomasks described above, the photoresist is exposed as follows. In other words, in the case of positive photoresist, the pattern to be transferred is transferred to the photoresist in the portion corresponding to the integrated circuit formation section, and at the same time, the photoresist in the portion corresponding to the wafer peripheral section is exposed, but the photoresist in the portion outside the integrated circuit is exposed. Portions of the photoresist corresponding to the sections are not exposed. In addition, in the case of a negative photoresist, at the same time that the pattern to be transferred is transferred to the photoresist in the area corresponding to the integrated circuit forming area, the photoresist in the area corresponding to the wafer peripheral area is not exposed, but the photoresist in the area outside the integrated circuit is not exposed. The photoresist in the corresponding area is exposed to light. Therefore, regardless of whether it is a positive type or a negative type, the photoresist in the area corresponding to the wafer peripheral area is removed by development, but the photoresist in the area corresponding to the area outside the integrated circuit remains attached to the semiconductor wafer. . Therefore, in the next ion implantation process, the semiconductor wafer can be fixed at the peripheral edge of the semiconductor wafer from which the photoresist has been removed, and the film deposited during the shipping process etc. can accumulate due to damage during ion implantation. This can prevent the film from peeling off from the out-of-circuit section.

On the other hand, when using the photomask according to the present invention in which no transferred pattern is formed in the integrated circuit forming section,
After exposure using a conventional photomask, exposure using a photomask according to the present invention may be performed. In this way, the photoresist in the portion corresponding to the wafer peripheral section can be removed by development without using a special exposure device for peripheral edge exposure.

[Example] A photomask according to an example of the present invention on which a pattern to be transferred is formed will be described based on FIG. 1 showing a plan view thereof.

In the figure, reference numeral 1 indicates a photomask used in a same-magnification exposure device, and the pattern of this photomask 1 corresponds to a wafer peripheral section 2 corresponding to the peripheral part of the semiconductor wafer 5 and an integrated circuit forming part of the semiconductor wafer 5. The wafer is divided into an integrated circuit forming section 3 and a non-integrated circuit section 4 located outside the integrated circuit forming section 3 and inside the wafer peripheral section 2. The boundary between the wafer peripheral section 2 and the outside integrated circuit section 4 is located, for example, several mm inside from a position corresponding to the side edge of the semiconductor wafer 5.

Further, the boundary between the outside integrated circuit section 4 and the integrated circuit forming section 3 corresponds to the outline of the integrated circuit forming portion of the semiconductor wafer 5.

Here, the wafer peripheral section 2 is a light-transmitting area when a positive photoresist is applied to the semiconductor wafer.

Furthermore, when the semiconductor wafer is coated with a positive photoresist, the outer integrated circuit section 4 is covered with a light-shielding thin film, for example, a chromium thin film, and serves as a light-shielding region.

In the integrated circuit forming section 3, an original pattern of an integrated circuit to be transferred, that is, a pattern to be transferred is formed.

A case will be described in which, for example, an ion implantation pattern is formed in a positive photoresist coated on a semiconductor wafer using the photomask 1 described above.

The positive photoresist from the side edge of the semiconductor wafer to several mm inside is exposed by the exposure light transmitted through the wafer peripheral section 2 of the photomask 1.

The positive photoresist in the area located inside the peripheral exposed area of the semiconductor wafer and outside the integrated circuit forming area is
Since the exposure light is blocked by the non-integrated circuit section 4 of the photomask 1, it is not exposed.

Furthermore, the pattern to be transferred drawn in the integrated circuit forming section 3 is transferred to the positive photoresist of the integrated circuit forming portion of the semiconductor wafer inside the positive photoresist.

Thereafter, by developing this semiconductor wafer, a predetermined pattern is formed in the positive photoresist of the integrated circuit forming portion of the semiconductor wafer. Further, while the positive photoresist is removed from the edge of the semiconductor wafer up to several millimeters inside, the positive photoresist remains attached to the periphery of the integrated circuit forming area.

Note that when a negative photoresist is applied to a semiconductor wafer, the wafer peripheral section 2 of the photomask 1 is covered with a light-shielding thin film and serves as a light-shielding region, while the outer integrated circuit section 4 is a light-transmitting region. It is said that In this case, as in the case of positive photoresist, a predetermined pattern is formed in the negative photoresist of the integrated circuit forming portion of the semiconductor wafer by exposure and development. Also,
While the negative photoresist is removed from the edge of the semiconductor wafer up to several millimeters inside, the negative photoresist remains attached to the periphery of the integrated circuit forming area.

Further, in the above embodiment, the pattern to be transferred is formed in the integrated circuit formation section 3, but the pattern is not limited to this, and it may be covered with a light-shielding thin film to serve as a light-shielding area. good.

In this case, after exposure with a conventional photomask, such a photomask may be used to expose only the photoresist at the peripheral edge of the semiconductor wafer.

As described above, by using the photomask 1 according to this embodiment, it is possible to perform exposure for removing photoresist from the peripheral edge of a semiconductor wafer at the same time as exposure for forming an integrated circuit.

Therefore, it is possible to achieve the effects of improving throughput and reducing costs.

Furthermore, if a photomask in which the integrated circuit forming section 3 is a light-shielding area is used, only the exposure for removing the photoresist from the peripheral edge of the semiconductor wafer can be performed using the same-magnification exposure apparatus.

Therefore, since a peripheral edge exposure device is not required, it is possible to reduce costs.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the above Examples and can be modified in various ways without departing from the gist thereof. Nor. For example, the original integrated circuit pattern to be transferred may be formed in the non-integrated circuit section 4.

In the above description, the invention made by the present inventor has mainly been explained in terms of the technology for manufacturing semiconductor devices, which is the background of the invention, but the invention is not limited thereto.

[Effects of the Invention] The effects obtained by typical inventions disclosed in this application are briefly explained below.

According to the invention as set forth in claim 1, there is provided a photomask compatible with a positive photoresist used in a same-magnification exposure apparatus, which comprises: a wafer peripheral section corresponding to a peripheral portion of a semiconductor wafer;
The pattern includes an integrated circuit forming section corresponding to an integrated circuit forming portion of the semiconductor wafer, and a non-integrated circuit section outside the integrated circuit forming section and inside the wafer peripheral section, and at least the wafer peripheral section. is configured as a light-transmitting area, and the area outside the integrated circuit is configured as a light-blocking area. Portions of the photoresist corresponding to the wafer peripheral sections can be exposed without exposing portions of the photoresist corresponding to the sections. Therefore,
Since a special exposure device for edge exposure is not required, costs can be reduced.

According to the invention set forth in claim 2, there is provided a photomask compatible with a negative photoresist used in a 1-magnification exposure apparatus, which includes a wafer periphery section corresponding to the periphery of a semiconductor wafer and an integrated circuit forming portion of the semiconductor wafer. The pattern includes a corresponding integrated circuit forming section and a non-integrated circuit section outside the integrated circuit forming section and inside the wafer peripheral section, and at least the wafer peripheral section serves as a light-shielding area and Since the out-of-circuit section is configured as a transparent area, after the pattern to be transferred is transferred, such a photomask is subsequently exposed using a 1-magnification exposure device, thereby exposing the photoresist in the portion corresponding to the wafer peripheral section. It is possible to expose portions of the photoresist corresponding to sections outside the integrated circuit without exposing the photoresist to light. Therefore, there is no need for a special exposure device for edge exposure, so costs can be reduced.

According to the invention described in claim 3, in the photomask according to claim 1 or 2, since a predetermined pattern is formed in the integrated circuit forming section, exposure for transferring the predetermined pattern and after development are performed. Exposure can be carried out simultaneously to leave photoresist deposited in portions corresponding to off-integrated circuit sections while removing photoresist in portions corresponding to wafer peripheral sections. Therefore, it is possible to improve throughput and reduce costs.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a photomask according to an embodiment of the present invention. 1... Photomask, 2... Wafer peripheral section,
3... integrated circuit forming section, 4... non-integrated circuit section, 5... semiconductor wafer.

Claims (1)

[Scope of Claims] 1. A photomask compatible with positive photoresist used in a same-magnification exposure apparatus, which includes a wafer peripheral section corresponding to the peripheral part of a semiconductor wafer, and an integrated circuit corresponding to an integrated circuit forming part of the semiconductor wafer. The pattern includes a circuit forming section and a non-integrated circuit section outside the integrated circuit forming section and inside the wafer peripheral section, and at least the wafer peripheral section serves as a light-transmitting area and the non-integrated circuit section is outside the integrated circuit forming section and inside the wafer peripheral section. A photomask characterized in that the sections are configured as light-shielding areas. 2. A photomask compatible with negative photoresist used in a same-magnification exposure device, comprising: a wafer peripheral section corresponding to the peripheral portion of a semiconductor wafer; an integrated circuit forming section corresponding to an integrated circuit forming section of the semiconductor wafer; The pattern includes a non-integrated circuit section outside the integrated circuit formation section and inside the wafer peripheral section, and at least the wafer peripheral section is configured as a light-shielding area and the non-integrated circuit section is configured as a light-transmitting area. A photomask characterized by: 3. The photomask according to claim 1 or 2, wherein a predetermined pattern is formed in the integrated circuit forming section.