JPH01238126A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To stabilize element characteristics while improving moisture resistance and temperature-cycling resistance by using an silicon nitride film through a sputtering method as a passivation film. CONSTITUTION:A P-N junction is formed on the main surface side of an silicon substrate 1, a silicon oxide film 2 is shaped onto the substrate 1, and an aluminum wiring 3 and an silicon chromium resistor 4 are formed. A silicon nitride film 5 is applied onto the silicon substrate 1 including the aluminum wiring 3 and the silicon chromium resistor 4 through sputtering in the atmosphere of the mixed gas of argon and nitrogen, employing silicon as a target. When the film thickness of the silicon nitride film 5 reaches 500Angstrom or more, the stopping power of contaminated ions and moisture is recognized, but the film thickness may be thickened to 1.0mum or more.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to passivation of semiconductor devices, and in particular,
The present invention relates to stabilizing the characteristics of polycrystalline semiconductor resistors or metal resistors formed on semiconductor substrates.

[Conventional technology]

Conventionally, in semiconductor devices, i-crystalline semiconductor resistors are used to increase the density of elements and obtain high resistance, and silicon chromium resistors are used to obtain high-precision resistors. Further, from the viewpoint of quality of the semiconductor device, particularly moisture resistance, a silicon nitride film produced by plasma CVD is used as the passivation film.

[Problem that the invention seeks to solve]

In the conventional semiconductor device described above, a silicon nitride film produced by plasma CVD is used as a padding film, so transistor characteristics and resistor characteristics vary due to silicon nitride film growth, subsequent wafer heat treatment, and heat treatment in the assembly process. do. In particular, semiconductor devices with polycrystalline semiconductor resistors and silicon chrome resistors that require high precision,
There are drawbacks such as lower yield and lower quality. Plasma C
The cause of the characteristic fluctuation due to the silicon nitride film produced by the VD method is as follows.
It is thought that the large amount of hydrogen contained in this film is the main cause, but it is not clear yet.

[Means for solving problems]

In order to solve the above problems, the method for manufacturing a semiconductor device of the present invention includes a step of forming a resistor layer such as a semiconductor resistor or a silicon chrome resistor and metal wiring on a semiconductor substrate, and a sputtering method for coating the resistor layer. and forming a silicon nitride film by. The silicon nitride film produced by the sputtering method causes little damage during deposition, does not deteriorate the device characteristics of semiconductor devices, can be grown at temperatures from room temperature to about 500°C, and has the ability to block external contaminant ions and moisture. Therefore, it is excellent as a passivation film. This silicon nitride film can be formed by sputtering using silicon as a target in an atmosphere of argon and nitrogen, or using silicon nitride as a target in an atmosphere of argon or nitrogen mixed therein.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a sectional view of one embodiment of a silicon semiconductor device of the present invention. In FIG. 1, a PN junction (not shown) is formed on the main surface side of a silicon substrate 1 using a conventional technique,
Furthermore, after forming a silicon oxide film 2 on the substrate 1, an aluminum wiring 3 and a silicon chrome resistor 4 are formed. The thickness of each of these films is 1.0μ, and 500 people are appropriate. Next, a silicon nitride film 5 of about 0.1 μm is deposited on the silicon substrate 1 including the aluminum wiring 3 and the silicon chrome resistor 4 by sputtering using silicon as a target in an argon and nitrogen mixed gas atmosphere. If the silicon nitride film 5 has a thickness of 500 Å or more, it will have the ability to block contaminant ions and moisture, but it may be made thicker than 1.0 μm.

FIG. 2 is a sectional view of a semiconductor device manufactured according to Example 2 of the present invention. The example shown in FIG. 2 is a semiconductor device having a polysilicon resistor, in which a desired PN junction (not shown), a polysilicon resistor 6 and an aluminum wiring 3 are formed using a conventional technique, and then a silicon nitride layer is formed using a sputtering method. 0.1 μm of silicon oxide film 7 was deposited using plasma vapor deposition method.
Approximately 0μ is deposited.

In this example, the passivation film is composed of a silicon nitride film 5 formed by sputtering as a contaminant and moisture blocking film, and a silicon oxide film 7 for increasing the mechanical strength particularly required for resin-sealed semiconductor devices. Therefore, a chemically and physically excellent semiconductor device can be obtained.

〔Effect of the invention〕

As explained above, the present invention provides a passivation film with
By using a silicon nitride film by sputtering,
It is possible to improve yield and stabilize device characteristics without causing characteristic fluctuations in semiconductor devices containing silicon chrome resistors or polycrystalline silicon semiconductors, and at the same time to obtain semiconductor devices with excellent moisture resistance and temperature cycle resistance. effective.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a semiconductor device according to an embodiment of the present invention;
FIG. 2 is a sectional view of a semiconductor device according to a second embodiment of the present invention. 1...Silicon base L 2,7...Silicon oxide film, 3...Aluminum wiring, 4...
...Silicon chromium resistor layer, 5...Silicon nitride film by sputtering method, 6...Polysilicon resistor layer. Agent Patent Attorney Oto Uchihara

Claims (1)

[Claims] Forming a resistor layer such as a polycrystalline semiconductor resistor or a silicon chrome resistor on a semiconductor substrate having a PN junction,
The method for manufacturing a semiconductor device further includes covering the resistor layer with a passivation film, the method comprising depositing a silicon nitride film as the passivation film by sputtering.