JPH08162540A - Semiconductor device - Google Patents

Abstract

PURPOSE: To reduce influence of stress of mold resin to an operation region of a pellet and to make physical characteristic of an entire of a pellet uniform by providing an uneven region wherein an element of the same kind as an inner circuit is formed to a corner region of a pellet. CONSTITUTION: In a semiconductor device which has an inner circuit having an MOS structure with a pellet 18, a gate electrode 9 provided to a region excepting a corner region of the pellet 18, an aluminum wiring 10, a diffusion layer region 11 and a contact 12 and is sealed with mold resin, an uneven region 1 wherein an element of the same kind as an inner circuit is provided to a corner region of the pellet 18. For example, the uneven region 1 which is unrelated to operation of a semiconductor device is arranged in a corner region of the pellet 18 of the MOS type semiconductor device. Although the uneven region 1 has gate polysilicon 2, 3, an aluminum wiring 4, a diffusion layer region 5 and a contact 6 and forms an MOS type structure, each region is electrically disconnected to an inner circuit.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, and more particularly to improvement of the influence of stress caused by encapsulation of a mold resin.

2. Description of the Related Art In order to reduce the area of a pellet of a semiconductor device, the operating area is used up to the effective area of the pellet, and the lead terminal of a lead frame having a lead terminal for external connection is used. Depending on the arrangement, the conventional semiconductor device pellet has an operating region even at the corners. As in today's semiconductor device technology, semiconductor device functions are required to be sophisticated, and the pellet area is increasing more and more. However, when the area of the pellets is increased, there is a drawback that the resin is easily affected by stress due to heating at the time of encapsulating the mold resin and expansion / contraction / curing shrinkage of the resin due to the low-high temperature cycle. It has been reported that the larger the area of the pellet and the further away from the center of the pellet, the more stress is applied, and there is a possibility that characteristic fluctuations may occur especially under the pellet angle region. ["Aluminum corrosion and stress due to water vapor on LSI chips sealed with plastic" (MOISTURE-IN
DUCED ALUMINUM CORROSIONA
ND STRESS ON THE CHIP IN
PLASTIC-ENCAPSULATED LS
_{I s, 1979, IEEE, CH1425-8} / 79 /
_oooo- see D11S]. An object of the present invention is to solve the above-mentioned problem with stress.

A semiconductor device according to the present invention comprises a pellet and an internal circuit provided in a region other than a corner region of the pellet and having a MOS type structure having a gate electrode, aluminum wiring, a diffusion layer region and a contact. In the semiconductor device encapsulated by the mold resin, the semiconductor device is characterized in that the corner region of the pellet has an uneven region in which an element of the same type as the internal circuit is formed.

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a schematic diagram showing a layout of a pellet corner region in one embodiment of the present invention. This embodiment is a MOS type semiconductor device, and 1 is an uneven region which is irrelevant to the operation of this semiconductor device and is arranged in the corner region of the pellet. 2 and 3 are gate polysilicon, 4 is aluminum wiring, 5 is a diffusion layer region, and 6 is a contact, which forms a MOS type structure, and each region is electrically isolated from the internal circuit. Next, 7 is a circuit region having the original operation of the semiconductor device, and 8 is an external connection pad. Reference numeral 9 is gate polysilicon, and 10 is aluminum wiring, both of which are connected to an internal circuit. Reference numeral 11 is a diffusion layer region, and 12 is a contact. FIG. 2 is a sectional view of the embodiment, and the cut surface is the first
It corresponds to between A and B in the figure. Reference numeral 13 is a semiconductor substrate, 14 is a mold resin, 15 is an oxide film for protecting pellets, 16 is a gate oxide film, and 17 is a lead frame on which pellets are mounted. As shown in FIG. 2, in a semiconductor device encapsulated in a mold resin, the mold resin, the semiconductor silicon, and the metal have different expansion coefficients, and a stress is applied by a temperature cycle or the like. In this embodiment, stress is applied in the direction indicated by arrow 19 in FIG. The magnitude of this stress increases as the distance from the center of the pellet increases, and becomes maximum in the pellet corner region. Therefore, by providing a concavo-convex region unrelated to the internal circuit in this corner region, stress concentrates on this concavo-convex region, and the original operating region is protected. Further, in the corner area of the pellet, a stress absorption area is formed which is electrically separated from the internal circuit and is formed by an element of the same kind as the element forming the internal circuit.
Therefore, the physical characteristics of the entire pellet of the semiconductor device can be made uniform. Although the MOS type semiconductor device has been described above, the same applies to other types.

As described above, according to the present invention, it is possible to obtain a semiconductor device in which the influence of the stress of the molding resin on the operating region of the pellet is reduced. Further, according to the present invention, a stress absorbing region is formed in the corner region of the pellet, which is electrically separated from the internal circuit and is formed by the same kind of device as the device forming the internal circuit. Therefore, the physical characteristics of the entire pellet of the semiconductor device can be made uniform.

[Brief description of drawings]

FIG. 1 is a schematic view showing a layout of an embodiment of the present invention,
FIG. 2 is a sectional view showing a state in which the semiconductor pellets are encapsulated in a mold resin in the embodiment of FIG. 1 ... uneven area, 2, 3, 9 ... gate polysilicon,
4.10 ... aluminum wiring, 5,11 ... diffusion layer region,
6, 12 ... Contact, 7 ... Operating area of semiconductor device, 8 ... Pad for external connection, 13 ... Semiconductor substrate, 1
4 ... Mold resin, 15 ... Oxide film for pellet protection,
16 ... Gate oxide film, 17 ... Lead frame.

Claims (1)

[Claims] A semiconductor device having a pellet and an internal circuit having a MOS type structure having a gate electrode, an aluminum wiring, a diffusion layer region, and a contact provided in a region other than a corner region of the pellet, the pellet being a mold device, the pellet comprising: 2. A semiconductor device having an uneven area in which the same kind of element is formed in the internal circuit in the corner area.