JP3351803B2 - Method for manufacturing semiconductor integrated circuit device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the manufacture of a semiconductor integrated circuit device having a plurality of functional blocks using an SOI substrate.
About the method .

In recent years, as semiconductor integrated circuits have become highly integrated and dense, signals in one functional block constituting the integrated circuit propagate to other functional blocks and become noise signals, which adversely affect the functional blocks. Interference of signals between functional blocks, which causes the deterioration of the function of an integrated circuit, has become a problem.

[0003] In order to solve this problem, there is a demand for a technique for separating each functional block constituting an integrated circuit from each other and eliminating mutual interference between the functional blocks.

[0004]

BACKGROUND ART FIG. 3, have a plurality of conventional functional blocks
FIG. 1 is a diagram showing an example of a semiconductor integrated circuit device .

[0005] The prior art shown in FIG.
(Silicon On Insulator) Using a substrate, trench
Each functional block that constitutes the integrated circuit is separated by
This is to prevent mutual interference of signals between functional blocks.

In FIG. 3, 31 is a supporting substrate, 32 is an insulator, 33 is a trench, and 34, 35 and 36 are island-shaped semiconductor regions.

In this conventional technique , a trench 33 reaching the insulator 32 is formed in a semiconductor layer on the surface of an SOI substrate manufactured by a usual method. As a result, the trench 33
A plurality of island-shaped semiconductor regions 34, 35 and 36 separated from each other by a, 33b, 33c and 33d are formed.

Each functional block constituting the integrated circuit is formed in a plurality of island-shaped semiconductor regions 34, 35 and 36 which are separated from each other.

[0009]

Oite the semiconductor integrated circuit device manufactured using the conventional technique shown in FIG. 3 [0007] is, between the plurality of island-shaped semiconductor regions 34, 35 and 36 which are separated from each other Capacitors are formed via the trenches 33a, 33b, 33c, 33d. As a result, the island-shaped semiconductor region 3
Mutual interference of signals occurs between the respective functional blocks constituting the integrated circuit formed in 4, 35 and 36.

[0010] Therefore, the conventional example has a problem that mutual interference of signals between functional blocks constituting an integrated circuit cannot be completely prevented.

[0011] An object of the present invention is to provide to enable you to completely prevent mutual interference between the functional blocks, the method for manufacturing a semiconductor integrated circuit device having the functional blocks of the multiple, this
Is to solve the above problem .

[0012]

In order to solve the above object, according to an aspect of the present onset Ming, and formed on the support substrate insulator insulating
SOI composed of a semiconductor layer provided on the surface of an edge
Using multiple substrates, each of which becomes a functional block
Manufacturing method of semiconductor integrated circuit device forming island-shaped semiconductor region
The semiconductor layer on the surface of the SOI substrate,
Forming a trench with a depth reaching the edge to form the plurality of islands;
Separate the semiconductor regions individually and provide a semiconductor outside the trench
The semiconductor region is fixed to a predetermined potential.
It is configured to be formed as an area.

FIG. 1 shows a semiconductor package manufactured according to the present invention.
FIG. 3 is an explanatory view of the principle of the integrated circuit device .

In FIG. 1, 1 is a supporting substrate, 2 is an insulator, 3 and 4 are trenches, 5 and 6 are island-shaped semiconductor regions, and 7 is a shielding semiconductor region.

Semiconductor integrated circuit device manufactured according to the present invention
In the arrangement, the individual island-shaped semiconductor regions 5 and 6 where the functional blocks constituting the integrated circuit are formed are surrounded by the trenches 3 and 4. The semiconductor layer outside the trenches 3 and 4 is fixed at a predetermined potential to form the semiconductor region 7 for shielding.

Therefore, between the island-shaped semiconductor region 5 and the island-shaped semiconductor region 6 where the functional blocks are formed, the shielding semiconductor region 7 shielded by a predetermined potential, for example, a power supply potential or a ground potential is interposed. Therefore, formation of a capacitance between the island-shaped semiconductor regions 5 and 6 can be prevented. As a result, mutual interference of signals between the functional blocks formed in the island-shaped semiconductor region 5 and the functional blocks formed in the island-shaped semiconductor region 6 can be completely prevented.

[0017]

FIG. 2 shows a semi-conductor manufactured according to one embodiment of the present invention.
It is a figure showing a conductor integrated circuit device .

In FIG. 2, reference numeral 11 denotes S as a support substrate.
i substrate, 12 is SiO ₂ as an insulator, 13 and 1
4 is a trench, 15 and 16 are island-shaped semiconductor regions made of n-type Si, 17 is a shielding semiconductor region made of n-type Si, and 18 is a p-type well formed in the island-shaped semiconductor region 16 made of n-type Si. , 19 are p ⁺ diffusion regions formed on the surface of the island-shaped semiconductor region 15 made of n-type Si, 20 are n ⁺ diffusion regions formed on the surface of the p-type well 18, 21
Is an n ⁺ diffusion region formed on the surface of the shield region 17 made of n-type Si, 22 is a surface protective film made of SiO ₂ ,
23 and 24 are poly Si gates, 25, 26 and 2
7 is an Al wiring.

The SOI substrate is manufactured by the following method.

(1) Melt recrystallization method This is a method in which polysilicon is deposited on an insulator, melted by an energy beam such as a laser beam, and crystal growth is performed while moving the melted portion.

(2) SIMOX method This is a method in which oxygen is ion-implanted into a silicon substrate and a high-temperature heat treatment is performed to form a silicon oxide film in the silicon substrate and leave a silicon crystal in an upper layer.

(3) Bonding method In this method, two silicon wafers are bonded via an oxide film formed on the front surface, and one silicon substrate is polished from the back surface to leave a thin silicon layer.

In the present embodiment, trenches 13 and 14 reaching the insulator 12 are formed in the semiconductor layer on the surface of the SOI substrate manufactured by these methods. As a result, the island-shaped semiconductor region 15 surrounded by the trench 13 and the island-shaped semiconductor region 16 surrounded by the trench 14
Is formed. Then, the trench 13 and the trench 1
4, a shield region 17 is formed.

Each functional block constituting the integrated circuit is formed in island-shaped semiconductor regions 15 and 16 made of n-type Si separated from each other. FIG. 2 shows an example in which a PMOS transistor is formed in the island-shaped semiconductor region 15 made of n-type Si and an NMOS transistor is formed in the island-shaped semiconductor region 16 made of n-type Si. The present invention is not limited to this. For example, a plurality of transistors of various types and passive elements such as resistors and capacitors may be formed in the island-shaped semiconductor regions 15 and 16 made of n-type Si to form desired functional blocks. it can.

On the other hand, the shielding semiconductor region 17 made of n-type Si is connected to the Al wiring 27 via the n ⁺ -type contact region 21. The Al wiring 27 is fixed to the power supply potential _VDD or the ground (GND) potential. As a result, the shield semiconductor region 17 made of n-type Si has a shield potential.

As described above, the semiconductor device manufactured according to this embodiment is
In the integrated circuit device , a shielding semiconductor region 17 made of n-type Si fixed at a shield potential is interposed between an island-shaped semiconductor region 15 made of n-type Si and an island-shaped semiconductor region 16 made of n-type Si. Therefore, the functional blocks formed in the island-shaped semiconductor region 15 made of n-type Si and the n-type Si
No capacitance is formed between the island-shaped semiconductor region 16 and the functional block.

As a result, mutual interference of signals between the functional blocks formed in the island-shaped semiconductor region 15 made of n-type Si and the functional blocks formed in the island-shaped semiconductor region 16 made of n-type Si is completely eliminated. Is prevented.

In this embodiment, an example is shown in which Si is used as the support substrate 11, but other semiconductors or insulators may be used. Although an example in which n-type Si is used for the island-shaped semiconductor region and the shielding semiconductor region 17 has been described, p-type Si and i-type Si may be used. Although an example in which SiO ₂ is used as the insulator 12 has been described, another insulator may be used. Wiring 25, 26
Although the examples using Al are shown in FIGS. 27 and 27, other conductive materials may be used.

[0029]

According to the present invention, in a semiconductor integrated circuit device having a plurality of functional blocks, mutual interference between the functional blocks can be completely prevented. Therefore, it greatly contributes to high integration and high density of the semiconductor integrated circuit device.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of a semiconductor integrated circuit device manufactured according to the present invention.

FIG. 2 shows a semiconductor integrated circuit manufactured according to an embodiment of the present invention.
It is a figure showing a road device .

FIG. 3 shows a conventional semiconductor integrated circuit having a plurality of functional blocks.
It is a figure showing an example of a circuit device .

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Support substrate 2 Insulator 3, 4 Trench 5, 6 Island-shaped semiconductor region 7 Semiconductor region for shielding

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-148855 (JP, A) JP-A-57-172739 (JP, A) JP-A-2-271567 (JP, A)

Claims (1)

(57) [Claims] An insulator formed on a supporting substrate and the insulator
Using an SOI substrate composed of a semiconductor layer provided on the body surface, a plurality of islands each serving as a functional block
In a method of manufacturing a semiconductor integrated circuit device for forming a semiconductor region, a semiconductor layer on a surface of the SOI substrate reaches the insulator.
Forming a trench having a depth to form the plurality of island-shaped semiconductor regions;
The method of manufacturing a semiconductor integrated circuit device, characterized in that individually separated, forming an outer semiconductor region of said trench, as a shield for a semiconductor region that will be fixed to a predetermined potential.