JPS5913332A - Semiconductor device - Google Patents

Abstract

PURPOSE:To stabilize the device electrically while improving humidity resistance property and alkali ion-resisting characteristics by coating the surface of a semiconductor pellet with a film consisting of a nonmetal and a metal from which a submetal is removed. CONSTITUTION:A PSG film 12 consisting of phosphorus silicate glass is formed onto a wiring layer 11 and a semiconductor substrate 10, and a contact hole 13 communicating with the wiring layer 11 is formed to the PSG film 12. The film 15 with a window 14 communicating with the hole 13 is formed onto the PSG film 12. The film 15 is formed by the nonmetal such as nitrogen and the metal such as nickel from which the submetal such as arsenic is removed. With the semiconductor device 20 constituted in this manner, corrosion is not generated even after forty-one cycles pass in a wiring corrosion evaluation test, and a ratio of a change to an initial current amplification factor after BT 100hrs is 98-99% in a degradation test of a current amplification factor by alkali ions, and wetproof property and the checking characteristics of alkali ions are excellent.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a semiconductor device.

[Technical background of the invention and its problems]

Conventionally, semiconductor devices using a P2O film as a passivation film have been used. This semiconductor device has a structure as shown in FIG.

In the figure, 1 is a semiconductor substrate on which desired elements are formed, and 2
is a wiring made of aluminum or the like formed on the surface of the substrate 1. The surface of the semiconductor pellet 3 made of the substrate 1 on which the elements and wiring 2 are formed is made of PSGSiO2.

For PSGSiO2 formation, the substrate 1 after the wiring 2 is formed is coated with C, V,
D, (Chemical Vapon Deposl)
After installing the reactor gas (s*n4-PH, -02) in the device and heating it to 300-500℃, half the amount of reaction gas (s*n4-PH,-02) is supplied so that the phosphorus concentration is 1.0-1.5X10 cm. However, a vapor phase growth process is performed until the thickness reaches 1.0 to 1.5 μm. In this way, the semiconductor device 1 using PSGSiO2 as a diffusion film can easily form PSGSiO2 at a relatively low temperature of 300 to 500°C, is electrically stable, and has a getter for Na in PSG4. It has advantages such as ring-like properties. However, PSGSi
Since it has O2 moisture, P2O5 in the PSG film 4 is eluted as phosphorus, pinholes are formed where P2O5 is concentrated, and the wiring 2 is corroded. the result,
However, there are semiconductor devices that use a plasma silicon nitride film (hereinafter referred to as P-8IN@) as a passivation film. To form a P-8iN film, first, a semiconductor substrate on which desired elements and wiring have been formed is placed in a plasma CVD apparatus C, the pressure is reduced to 0.5 to 2.0 Torr, and then heated to a temperature of 150 to 400°C.

Next, 5IH4-NH3 is supplied as the 'C1 reaction gas, and high frequency is applied to turn the reaction gas into plasma to transform it into 1.
This is done by depositing to a thickness of 0 to 1.5 μm.

A semiconductor device having such a P-8iN film has a thickness of 250
~400. A P-81N film can be formed at a relatively low temperature of tl:, has excellent alkali ion blocking properties, and is not hygroscopic. However, since the P-8IN film is easily charged, it has a drawback of poor low current operation characteristics.

[Purpose of the invention]

An object of the present invention is to provide a semiconductor device that is electrically stable and has excellent moisture resistance and alkali ion resistance.

[Summary of the invention]

The present invention provides a semiconductor device which is electrically stable and has improved moisture resistance and alkali ion resistance by coating the surface of a semiconductor pellet with a film made of a metal other than nonmetals and semimetals. It is.

[Embodiments of the invention]

Examples of the present invention will be described below.

Figure 2 is a cross-sectional view of one embodiment of the present invention.
is a semiconductor substrate on which desired elements are formed. On the semiconductor substrate 10, a wiring layer 11 of a predetermined pattern made of aluminum or the like is formed. On the wiring layer 11 and the semiconductor substrate 10, a PSG film 1 made of phosphorus silicate glass is disposed.
2 is formed. A contact hole 13 communicating with the wiring layer 11 is formed in the PSG film 12 . P.S.G.
A film 15 having a chamber 14 communicating with a contact hole 13 formed in the wiring layer 11 is formed on the film 1 and the film 2 . The coating 15 is made of a metal such as nickel, excluding a nonmetal such as nitrogen or a semimetal such as arsenic.

The semiconductor device U configured as described above can be manufactured, for example, as follows. First, as shown in FIG. 3(2), a wiring layer 11 made of pure aluminum or the like is formed on a semiconductor substrate 10 on which desired elements are formed. Then,
This semiconductor pellet on which the element and wiring layer 11 are formed is C, 'V, D, and the packaging is inside: fffJl,! J>m
Power 0.5 x 102! ffi', raw tm[14o
A PSG film 12 made of phosphorus silicate glass is formed to a thickness of 1.0 μm on the semiconductor substrate 10 and wiring '11 under the following conditions: oc, pressure jJ 760 Torr, and processing time 25 minutes. Next, a photoresist film 16 with a predetermined gloss is formed on the PSG film 1, and using this as a mask, ammonium fluoride etching solution (F:CH3CO0H=2:
The wiring layer 11 is etched according to the L volume ratio).
A contact hole 13 communicating with is opened. Next, as shown in FIG. 3B, after removing the photoresist film 16,
193.04m of new photoresist using spin foot method
tt on the exposed wiring 1 and on the PSG film 1 and 2 with a thickness of
Then, patterning is performed so that the resist film 17 remains only in the contact hole 13 portion. Next, as shown in FIG. A beam type was used, and the evaporation conditions were an initial vacuum level of 1°0XIO Torr before evaporation, and a vacuum level of 3, OX during evaporation.
The deposition time was 40 minutes at 10" Torr and a film growth rate of 500"/mtn. Thereafter, the resist film 17 formed on the contact hole 13 was removed using an organic resist stripping method, and the film 16 on the resist 17 was lifted off, washed with water, and dried to form the structure shown in FIG. A semiconductor device as shown is obtained.

In order to confirm the effect of the semiconductor device L1 configured in this way, a wiring corrosion evaluation test was conducted on 100 semiconductor devices L1 of the example, and the results shown by the characteristic line (1) in FIG. 6 were obtained. Ta. In addition, alkali ions (especially Na
), we conducted a current amplification factor deterioration test, and Figure 7 shows the characteristic 11! The results shown in +(1) were obtained. In order to conduct these reliability tests, the wiring layer 11 made of aluminum was
As shown in Figure 8, the width is 8 μm, the total length is 4.0 μm, the thickness is 1
．． 0 μm and 2 layers on the semiconductor substrate 1o at intervals of 10 μm.
The main form was powerful. In addition, in order to evaluate the alkali ion blocking property by changing the current amplification factor (bym), the semiconductor substrate 1
Two NPN type bipolar transistors were formed on the substrate 0.

Note that the semiconductor device 20 is made of phenolic resin.
J? sealed in a package. In addition, for the corrosion J/P value test, a saturated steam exposure test (hereinafter referred to as P, C, T test) was conducted continuously for 20 hours in 2.5 atmospheres of steam, and then a bias temperature test ( B, T, test) at 85℃
The measurement was carried out under the condition of an applied voltage of 15 V for 20 hours.

The process of this series of measurements was defined as one cycle, and the corrosion resistance was evaluated from the characteristic of the cumulative failure rate due to corrosion with respect to the number of cycles. Further, the current amplification factor deterioration test due to alkali ions was conducted under the conditions of a temperature of 125°C.0 and an applied voltage of 15V.

Next, other embodiments of the present invention will be described.

FIG. 4 is a sectional view of another embodiment of the invention. 3 in the diagram
0 is a semiconductor substrate on which desired elements are formed, and a wiring layer 31 of predetermined i9 turns made of aluminum or the like is formed on its surface. Wiring layer 3 and semiconductor substrate 3
Three PSG films made of phosphorus silicate glass are formed on top of the three films. A contact hole 33 communicating with the wiring layer 31 is formed on the PSG film 3 2 .

A coating 35 made of aluminum or the like and having a window 34 communicating with the contact hole 33 is formed on the PSG film 32 . A metal compound layer 36 made of an aluminum oxide film or the like is formed on the surface of the film 35 and the window 34 .

Semiconductor device L configured in this way! According to, for example, it can be manufactured as follows. First, Figure 5 (
As shown in (g), a semiconductor substrate 3o on which desired elements are formed.
A wiring layer 31 made of pure Al, 1N, etc. is formed thereon. Next, the surface of the semiconductor pellet on which the element and wiring layer 31 have been formed is coated with the PSG film 3 made of phosphorus silicate glass using the C, V, D method under the same conditions as in the example. .0μm is formed. Next, this was placed in a vacuum evaporation device, and a layer of 2.1# thick was deposited on the top two surfaces of the three PSG films.
A coating 35 made of pure aluminum of I was formed. An electron beam type vacuum evaporation device was used. The vapor deposition conditions were an initial vacuum level of 1. OX 10 Torr,
Vacuum degree during vapor deposition 3. OX 10-'Torr, film growth rate 2500''/H1□, and vapor deposition time approximately 8 minutes and 30 seconds.Next, as shown in FIG. , aluminum etching solution (phosphoric acid: acetic acid; nitric acid: pure water = 76:15
:3:5, volume ratio) to form a film 3.
5, the window 34 is opened. Next, in the same figure (as shown in Q,
After peeling off the photoresist film 35ILt, accelerated chromium oxidation method (5 thichromic acid solution, current density 0.15 A/,
2. An oxidation treatment is performed at a voltage of 40 V, a liquid temperature of 35° C., and a treatment time of about 2 minutes) to form a metal compound layer 36 made of an aluminum oxide film on the surface of the metal film 35.

Thereafter, this was washed with water, and RIB method (CF4: H2=
20 SCCM: 10 SCCM, output 350W
, :r-,y PS at a switching rate of 550X/m1n)
A contact hole 33 communicating with the two-line layer 31 is opened on the G film 3 to obtain a semiconductor device 40 as shown in FIG.

In order to confirm the effectiveness of this semiconductor device 40, a reliability test was conducted under the same conditions as described above, and a curve (II) shown in FIG. 6 was obtained as a result of the corrosion evaluation test. In addition, as a result of a deterioration test of the current amplification factor due to alkali ions, a song M (n/) shown in FIG. 7 was obtained.

For comparison with Examples, P was used as the passivation film.
Similar reliability tests were conducted on a conventional semiconductor device having an SG film (Comparative Example 1) and a conventional Gyudou Nenso W having a P-8iN film as a passivation film (Comparative Example 2). The results shown by the curve ■ in Figure 6 and the curve ml in Figure 7 were obtained, and for the latter, the curve (
), the results shown in curve 4 in Figure 7 were obtained.

As is clear from the results shown in FIG. 6, no corrosion was observed in both of the semiconductor devices 20 and 40 of the example even after 41 cycles. However, in the semiconductor device of Comparative Example 10, corrosion was observed from the 5th cycle, and in the semiconductor device of Comparative Example 2, corrosion was found to occur from the 15th cycle. In other words, it can be seen that the semiconductor device 20LJL of the example has much better moisture resistance than those shown in Comparative Examples 1 and 2.

Further, as is clear from the results shown in FIG. 7, in the semiconductor device 1f process 1 of the example, the rate of change with respect to the initial current amplification factor (hyx) after 100 hours of BT was 98
~99 inches, and in the semiconductor device of Comparative Example 1, it was 76 inches,'
Since the semiconductor device of the comparative example has a resistance of 90 cm, it can be seen that the semiconductor device 1Mu of the example has extremely excellent alkali ion blocking properties. In addition, the semiconductor device uju of the example has excellent moisture resistance and alkali ion blocking properties, making it a highly reliable innovator! It can be seen that it has a basic effect.

Further, since the surface of the semiconductor device 1fiu of the embodiment is covered with at least the film 16.35, the potential is set to the ground level, and it has electrostatic, magnetic, and electromagnetic shielding effects. .

Incidentally, in the semiconductor device L1 of the example, it was experimentally confirmed that an electromagnetic interference effect appears at frequencies of 200 MHz or higher. Further, it was experimentally confirmed that the semiconductor device uJLl of the example has excellent radiation resistance, particularly α-ray resistance.

〔Effect of the invention〕

As explained above, the semiconductor device according to the present invention is electrically stable and has remarkable effects such as being able to improve moisture resistance and alkali ion resistance.

[Brief explanation of the drawing]

It's Fig. 1 is a cross-sectional view of a conventional semiconductor device, Fig. 2 is a cross-sectional view of an embodiment of the present invention, and Fig. 3) to (
C'l is an explanatory diagram showing the manufacturing method of the semiconductor device according to the same embodiment in order of steps, and FIG. 4 is a cross-sectional view of another embodiment of the present invention.
5) to the same figure (Q is an explanatory diagram showing the process order of the semiconductor device manufacturing method of the assimilation example, FIG. 6 is a characteristic diagram showing the relationship between the cumulative failure rate and the number of cycles, Figure 7 is
FIG. 8, which is a characteristic diagram showing the relationship between the rate of change in current amplification factor and the BT processing time, is a plan view of the pattern of the wiring layer used for the reliability test. 1o, so... Semiconductor substrate, 11.31... 6 self-line layer, 12.32... P8G film, 13.33... Contact hole, 14.34... Window, 15y35...
Coating, 36...metal compound layer, Ll, Lj...! 1
conductor device

Claims (2)

[Claims] (1) Semiconductor device 0 characterized in that the surface of a semiconductor pellet on which a predetermined element is formed is covered with a film made of metal excluding nonmetals and semimetals. (2) The semiconductor device according to claim 1, wherein a metal compound layer is formed on the metal film.