JPS63169047A - Semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a reflow having large step moderation at lower temperature by forming a nitride film under the BPSG film of a semiconductor device in which the BPSG film is used as an interlayer film to allow the BPSG film to reflow in a steam atmosphere. CONSTITUTION:An oxide film 16 and a nitride film 17 are grown on a P-type MOS with a polycrystalline silicon film 15 as a gate material on an N-type silicon substrate 11, and a BPSG film 18 is grown thereon. A hole is opened in the same shape as that of a contact at part of the film 17 at a contact part 19, and the film 17 is always formed at a lower layer of the film 18 at the part except the hole. That is, the film 17 is formed under the film 18 to eliminate the oxidation of a P-type diffused layer region 12 to cause a P-type diffused layer resistance to rise. After the film 18 reflows, the contact part 19 is opened by PR technique and dry etching technique, heat treated in a nitrogen atmosphere, thereby alleviating the step of the contact part 19.

Description

DETAILED DESCRIPTION OF THE INVENTION 1] Industrial Application Field The present invention relates to a semiconductor device, and particularly to a semiconductor device using a BP8G film for the glabellar membrane.

(Prior Art) Conventionally, a Bpsc; film has generally been used as an interlayer film of a semiconductor device.

1) Problems to be Solved by the Invention] In the structure of such a conventional interlayer film, the interlayer B1)S
As a GIli glue flow, heat treatment cannot be performed in a steam atmosphere where a glue flow effect for alleviating the step difference in the interlayer film can be obtained in a short time by processing at a lower temperature. That is, heat treatment cannot be carried out in a water vapor atmosphere because oxidizing species easily pass through the [3PSG film and violently oxidize the silicon substrate, polycrystalline silicon film, etc. below the BeSO4 film. For this reason, heat treatment in a nitrogen atmosphere has been carried out for conventional interlayer films even though it is known that the flow effect is small. For this reason, VJ3:i of recent L conductor devices has had the problem of going against the trend toward lower temperatures.

An object of the present invention is to provide a semiconductor device that has a high reflow effect and can be processed at a lower temperature in a shorter time.

1 Means for Solving Problems 1 The present invention provides a semiconductor device using a HP SC film as an interlayer film.
The wiring layer is insulated by a S G layer, and a nitride film is uniformly formed in a region between the Bp sc film and the interconnect layer except for one contact portion.

In other words, in the conventional interlayer film structure using only the BITIS film as described above, it is necessary to consider the manufacturing and dyeing of the i-guiding device, that is, the heat treatment dyeing for reflow of one layer. In the present invention, this structure is solved by forming at least a nitride film between the insulating interlayer film and the wiring layer to make it more uniform.

(Example j) Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view for explaining the first embodiment of the present invention, and in particular, a part of the cross-section of a p rr:i MOS semiconductor device is schematically shown.

As shown in FIG. 1, an acid-1 arsenic film 16 is placed on a P-type MO8 made of polycrystalline silicon 15 as a GaI material on an N-type silicon substrate 11. The nitride film 17 is grown and -ε is 1. This is a structure in which a thin PSG film 18 is grown. In addition, in =1 tank 1 part 19, =1 tank I is applied to a part of the nitride film 17.
It has the same shape as , and has a hole, but in other parts α), a nitrogen film 17 is always formed below the SG film 18.

Next, the manufacturing process of the first embodiment will be explained. First, on the N-type silicon substrate 11-H, a thick field oxide film 13 is formed using the OS method.
['After forming a film of about 1 layer by thermal oxidation, a variable strength film of about 400 layers is grown as the gate oxide film 14 by thermal oxidation. Next, a dodecrystalline silicon film doped with impurities is grown on the entire surface, and after patterning the polycrystalline silicon film for metal and wiring parts using PR technology, a polycrystalline silicon film 15 is formed into a shape 1'' ( Next, the oxide film 16 is formed by oxidation for 10 minutes in a steam atmosphere at 900° C. Next, the N-type silicon substrate 11 on which the oxide film 16 is formed is
11' CVD method is used to deposit nitrided 1 pattern 17 on top to a thickness of 10
00 people will grow uniformly. After that, BPS
G film 18 was formed to a thickness of 1000 (') by normal pressure CVD method.
After a certain degree of growth, heat treatment is performed for 20 minutes in a steam atmosphere at 900°C. This heat treatment alleviates the difference in film strength of r(PSG film 1).On the other hand, in the conventional heat treatment in the water or steam atmosphere, the surface of the P-type diffusion layer region 12 is oxidized and the I]-type diffusion layer is oxidized. However, as in this first embodiment, B f' S
(-; By forming the 9. S.G.
After reflowing the film 18, one contact part 19 is opened using the I''R technology and dry etching technology and heat treated in a nitrogen atmosphere at 900°C.
Alleviate the difference in level. Finally, aluminum is deposited one by one on the surface of this contact I portion 19 by sputtering.
Aluminum wiring 20 for wiring is formed using PR technology and dry etching technology.

FIG. 2 is a sectional view of a semiconductor device for explaining a second embodiment of the present invention. This second embodiment is 2 Jf? J
B P S G l model and two layers of nitride film and two
An I transistor using a layer of polycrystalline silicon film;
': are doing.

As shown in FIG.
A first nitride film 26 is formed on the right 1°. Further, the first polycrystalline silicon film 25 is used as a so-called gate polysilicon film, and the second polycrystalline silicon film 11Q 2
Use Q as wiring. In order to insulate this second polycrystalline silicon film 29 and aluminum wiring 34, a second I3P
The S G film 32 is formed, and its first layer includes the first nitride film 20 under the S G I film 27.
A second nitride film 31 is formed similarly. By these nitriding methods, each II P SC; membrane: g7
．． During the glue flow for ′-i2, the base “゛-type series =
1 J,! : Reflow can be performed without oxidizing the plate 21 and the first and second polycrystalline silicon films 25 and 29. In addition, since the nitride film 26, 31 is formed on each RF' S G film, each B P S G film 27, 32 is formed at a lower temperature in a steam atmosphere. Can be reflowed.

Next, the manufacturing process of this second embodiment will be explained.

First, the steps up to the reflow of the first r3rSG film 27 are the same as in the first embodiment. In this second example,
After opening the first contacts 1 to 28, the two first polycrystalline silicon films are 1. ,, Thickness 4 by PCV I) method
After that, the oxide film 30 is grown by heating at 900° C. for 10 minutes in a steam atmosphere. Next, a second nitride F film 31 is placed on top of this oxide film 30.
After growing by CVD method, the second B[)SG film 3
2 is grown, then heat treated in a steam atmosphere and reflowed. Finally, the second contacts 1 to 33 are opened and the aluminum wiring 34 is formed. In this way, the multilayer B
Even when the P S CR film 27.32 is used as an interlayer film, a nitride film 26.31 is formed under each B P S G film to prevent B P S G in a water vapor atmosphere.
Membrane flow can be carried out at lower temperatures. In particular, the effect of reducing heat treatment is very large.

Although two embodiments have been described, BPS (:
The nitride film formed directly below the film is not limited to these 11PS (the same performance can be achieved even if there is an oxide film or PSG film grown by atmospheric pressure CVD between the i film and the nitride film). Ru.

1 Advantages of the Invention 1 As explained above, the present invention provides a semiconductor device using a BPSG film as an interlayer film, in which B1+8(',
y The existence of the nitride film under the film enables the BPSG film to flow in a water vapor atmosphere, and also enables reflow at a lower temperature and with greater relief of steps than reflow in a nitriding atmosphere. This has the effect of realizing I7-.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a semiconductor device for explaining a first embodiment of the present invention, and FIG. 2 is a cross-sectional view of a semiconductor device for explaining a second embodiment of the present invention. 11... N silicon substrate, 12... 1) type diffusion layer region, I3... Field oxide film, 14... Gate oxide film, 15... Polycrystalline silicon film, 16... Oxide film , 17... Nitride film, 18... BPSGW; 4.19
...Contact part, 20...Aluminum wiring, 21...
・P-type silicon plate, 22...N-type diffusion layer region, 23
...Field acid 1 arsenic film, 24...Gate oxide film,
25... First polycrystalline silicon film, 26... First nitride film, 27... First r31) S (i film, 28
...First contact portion, two...Second polycrystalline silicon film, 30...Oxide film, 31...Second nitride film, 32...Second B P S G Membrane, 33...2nd
Contact part, 34...aluminum wiring. ;+it,”11 Agent Patent Attorney Uchihara 4. ~, Figure 7

Claims (1)

[Claims] In a semiconductor device using a BPSG film as an interlayer film,
A semiconductor device comprising a BPSG film, a wiring layer insulated by the BPSG film, and a nitride film uniformly formed in a region between the BPSG film and the wiring layer and excluding a contact portion.