JPH08236534A - Formation of passivation film for semiconductor element - Google Patents

Abstract

PURPOSE: To inhibit the generation of hillocks on uppermost Al wiring layers and also conduct efficiently the recovery of a device from damage to the device by a method wherein after the uppermost Al wiring layers are formed, a direct single-wafer type plasma nitride film is formed without performing an H2 sintering treatment and thereafter, an annealing is performed. CONSTITUTION: Uppermost Al wiring layers 12 are formed and thereafter, a direct single-wafer type plasma nitride film 13 is formed on the gas condition of SiH4 gas of 12 to 22cc/1, NH3 gas of 10 to 15cc/1 and N2 gas of 420 to 850cc/1 without performing an H2 sintering treatment and thereafter, an annealing is performed. For example, the layers 12 are formed on a semiconductor substrate 11 formed with an element, such as a transistor. Then, a direct single-wafer type plasma nitride film 13 is formed on a prescribed gas condition without performing an H2 sintering treatment. After that, a passivation annealing is performed and a passivation process ends. Thereby, the amount of heat, which is applied to the wiring layers 12, is suppressed low and the generation of hillocks on the wiring layers 12 can be suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a passivation film of a semiconductor device.

[0002]

2. Description of the Related Art Conventional techniques in this field include:
For example, there were the following. FIG. 2 is a cross-sectional view of the manufacturing process of such a conventional semiconductor device. (1) First, as shown in FIG. 2A, after forming an uppermost Al wiring 2 on a semiconductor substrate 1 on which elements such as transistors are formed, an H ₂ sintering ( 400 ° C. × 30 minutes).

(2) Next, as shown in FIG. 2B, the PSG film 3 at normal pressure is formed. (3) Next, as shown in FIG. 2C, a batch type plasma nitride film (PE-SiN) 4 is formed. Here, the plasma nitride film 4 is formed to improve the moisture resistance, and the PSG film 3 is formed to relieve the stress of the plasma nitride film 4. (4) Finally, as shown in FIG. 2D, passivation annealing (350 ° C. to 400 ° C. × 30 minutes) is performed,
Again, the damage of the element is recovered.

[0004]

However, in the conventional method for manufacturing a semiconductor element described above, when H ₂ sintering is performed, a protrusion called a hillock 5 appears in the Al wiring 2 and is severe. Had a problem of short-circuiting with the adjacent Al wiring. INDUSTRIAL APPLICABILITY The present invention eliminates the above-mentioned problems, suppresses the occurrence of hillocks in the uppermost Al wiring, and efficiently recovers the damage to the device, so that a highly reliable device without short circuit can be manufactured. It is an object of the present invention to provide a method for forming a passivation film for a semiconductor element.

[0005]

In order to achieve the above object, the present invention provides (A) a method of forming a passivation film of a semiconductor device, which comprises performing a H ₂ sintering process after forming an uppermost Al wiring (12). Without directly performing single-wafer plasma nitride film (1
3) is formed and then annealing is performed.

(B) In the method for forming a passivation film of a semiconductor device, after forming the uppermost Al wiring (22), a single wafer type plasma oxide film (23) is formed without performing H ₂ sintering treatment, and thereafter, Is coated with SOG (24), and subsequently, a single-wafer type or a batch type plasma nitride film (25) is formed and annealed.

(C) In the method of forming a passivation film for a semiconductor device according to (B), the single-wafer plasma oxide film (23) has a refractive index of 1.49 to 1.55.

[0008]

[Action]

(1) According to the method for forming a passivation film for a semiconductor device according to claim 1, the single-wafer plasma nitride film is directly formed after the Al wiring is formed without performing the H ₂ sintering process. , The amount of heat applied to the Al wiring is suppressed to a low level, and the occurrence of hillocks can be suppressed.

The plasma nitride film formation conditions are N-
Since H bonds are generated under the condition that many H bonds are generated, a large amount of H ₂ is generated during the passivation annealing, and the damage of the device can be efficiently recovered. (2) According to the method for forming a passivation film of a semiconductor device according to claim 2, the single-wafer plasma oxide film is formed without performing the H ₂ sintering process after forming the Al wiring. The amount of heat applied to the Al wiring can be suppressed to a low level, and hillock generation can be suppressed.

After that, SOG is applied, then a single-wafer or batch-type plasma nitride film is formed, and annealing is performed thereafter. Therefore, H ₂ O desorbed from SOG is formed.
However, since it is converted into H ₂ when passing through the plasma oxide film, the damage of the device can be efficiently recovered. Furthermore, the growth of hillocks is suppressed by the plasma oxide film, and a highly reliable device without a short circuit of wiring can be manufactured.

Further, since the single-wafer plasma oxide film has a refractive index of 1.49 to 1.55, H ₂ O desorbed from SOG can be efficiently converted into H ₂ . By the way, when the refractive index becomes 1.45, H ₂ desorbed from SOG
O penetrates the single-wafer plasma oxide film as it is, which is a problem.

[0012]

Embodiments of the present invention will be sequentially described below with reference to the drawings. FIG. 1 is a sectional view of a semiconductor device manufacturing process showing a first embodiment of the present invention. (1) First, as shown in FIG. 1A, the uppermost Al wiring 1 is formed on a semiconductor substrate 11 on which elements such as transistors are formed.
Form 2

(2) Next, as shown in FIG. 1B, after forming the uppermost Al wiring 12, the single-wafer plasma nitride film 13 is directly formed without H ₂ sintering treatment. (3) Next, as shown in FIG. 1C, thereafter, passivation annealing is performed to complete the passivation process. At this time, the conditions for forming the single-wafer plasma nitride film are:
SiH ₄ flow rate as low as 12-22 cc / l, NH
₃ is 10 to 15 cc / l, N ₂ is 400 to 850 cc / l
Let l. As a result, the plasma nitride film has a large N—H bond, a large amount of H ₂ is desorbed during annealing, and the device can be efficiently recovered from damage. This makes it possible to compensate for the elimination of the H ₂ sintering process.

FIG. 3 is a sectional view of a semiconductor device manufacturing process showing the second embodiment of the present invention. (1) First, as shown in FIG. 3A, the uppermost Al wiring 2 is formed on a semiconductor substrate 21 on which elements such as transistors are formed.
Form 2 (2) Next, as shown in FIG. 3B, a single-wafer plasma oxide film 23 is formed in a thickness of about 1000 to 3000 liters.

(3) Next, as shown in FIG.
The OG 24 is formed by the rotation method. (4) Subsequently, as shown in FIG. 3D, the plasma nitride film 25 is formed by either a single wafer method or a batch method. (5) Finally, as shown in FIG. 3E, passivation annealing is performed. As the conditions for producing the single-wafer plasma oxide film, the pressure is 1.8 to 2.2 Torr, SiH ₄ is 6.5 to 11.0 cc / l, and N ₂ O is 170 to 260 c.
c / l, a film having a refractive index of 1.49 to 1.55 was prepared,
use.

Since the single-wafer plasma oxide film has a refractive index of 1.49 to 1.55, H desorbed from SOG is used.
₂ O can be efficiently converted to H ₂ . For example,
When the refractive index is 1.45, H ₂ O desorbed from SOG directly passes through the plasma oxide film, which is a problem. The present invention is not limited to the above-described embodiments, and various modifications can be made based on the spirit of the present invention, and these modifications are not excluded from the scope of the present invention.

[0017]

As described in detail above, according to the present invention, the following effects can be achieved. (1) According to the invention of claim 1, in the step of forming the passivation film of the semiconductor element, after the Al wiring pattern is formed, the single-wafer plasma nitride film is directly formed without performing the H ₂ sintering process. Therefore, the amount of heat applied to the Al wiring can be suppressed low, and the generation of hillocks can be suppressed.

The plasma nitride film formation conditions are N-
Since the H-bonds are generated under a large number of conditions, a large amount of H ₂ is generated during the passivation anneal, the damage to the device can be efficiently recovered, and a highly reliable device without a short circuit can be manufactured. . (2) According to the invention of claim 2, after the Al wiring is formed,
Since the single-wafer plasma oxide film is formed without performing the H ₂ sintering process, the amount of heat applied to the Al wiring can be suppressed to a low level, and the generation of hillocks can be suppressed.

After that, SOG is applied, then a single-wafer or batch-type plasma nitride film is formed, and annealing is performed thereafter. Therefore, H ₂ O desorbed from SOG is formed.
However, since it is converted into H ₂ when passing through the plasma oxide film, it is possible to efficiently recover the damage to the device. Furthermore, the growth of hillocks is suppressed by the plasma oxide film, and a highly reliable device without wiring short circuit can be manufactured.

As a further effect, as the wiring width becomes narrower, the coverage of the plasma nitride film deteriorates, and the moisture resistance of the device deteriorates.
By coating, the coverage and moisture resistance of the plasma nitride film are significantly improved. Since the single-wafer plasma oxide film has a refractive index of 1.49 to 1.55, S
H ₂ O desorbed from OG can be efficiently converted to H ₂ .

[Brief description of drawings]

FIG. 1 is a sectional view of a semiconductor device in a manufacturing process showing a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a conventional semiconductor device manufacturing process.

FIG. 3 is a sectional view of a semiconductor device in the manufacturing process showing the second embodiment of the present invention.

[Explanation of symbols]

 11, 21 Semiconductor substrate 12, 22 Top layer Al wiring 13 Single wafer type plasma nitride film 23 Single wafer type plasma oxide film 24 SOG 25 Plasma nitride film (single wafer type or batch type)

Claims (2)

[Claims] 1. A single-wafer plasma nitride film is directly subjected to S treatment without performing H ₂ sintering after forming the uppermost Al wiring.
iH ₄ 12-22 cc / l, NH ₃ 10-15 cc /
1, N ₂ 420 to 850 cc / l under gas conditions,
A method for forming a passivation film of a semiconductor device, characterized by performing annealing thereafter. 2. A single-wafer plasma oxide film having a pressure of 1.8 to 22 Torr and SiH ₄ 6.5 to 11 cc / without H ₂ sintering treatment after forming the uppermost Al wiring.
l, N ₂ O 170-260 cc / l gas conditions to form a film having a refractive index of 1.49-1.55, and then SOG is applied, followed by a single-wafer type or batch type plasma nitride film. A method of forming a passivation film for a semiconductor device, which comprises forming and annealing.