JPS59208860A - Semiconductor device - Google Patents

Abstract

PURPOSE:To remove defective factors, such as H2, H2O, etc. having an adverse effect on a semiconductor device by incorporating an adsorbent into the cavity of a semiconductor package. CONSTITUTION:A metallized layer 7 consisting of an Mg group alloy as a hydrogen adsorbent is formed on the back, the cavity side, of a cap 1 for a cerdip type semiconductor package, and a porous alumina layer 8 as a moisture adsorbent is formed to one part on the surface of the metallized layer 7. It is desirable that the Mg group alloy, such as an alloy consisting of Mg and Ni, an alloy consisting of Mg and Cu or the like is used as the hydrogen adsorbent employed. An alloy or a metal adsorbing hydrogen, such as a Pd metal, an LaCo alloy or the like may be used as other metals or alloys.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a technique that is effective when applied to semiconductor devices, and in particular to a technique that is effective when applied to a technique for removing hydrogen and moisture in a cavity of a semiconductor package. It's about technology.

[Background technology]

As is well known, semiconductor devices are susceptible to the effects of water vapor, etc. These influences change their characteristics, causing semiconductor devices to deteriorate.
In order to prevent semiconductor devices (bullets) from becoming defective and becoming unusable, hermetic seals, resin molds, etc. are used to protect them from the outside air.

However, in the cavity formed in the semiconductor package to seal the pellet, H20JPH,
Experiments conducted by the present inventor have revealed that there are gaseous substances in the pond and that these have an adverse effect on semiconductor devices. It refers to a space that is isolated from the outside by a package.For example, a ceramic type semiconductor package is used to place a semiconductor element in the semiconductor element mounting area (groove) of a base substrate (die bonding). After wire bonding with the leads, a cap is used as a sealing material such as AU-8n brazing material or low-melting glass to cover the semiconductor package. corresponds to

These H, H, and O'P gaseous substances that have an adverse effect on semiconductor devices are generated in various ways during the manufacturing process of semiconductor devices and from the materials used, and may remain in the cavity even after sealing or may be introduced. It's coming.

The causes of the generation of the gaseous substances as revealed by the inventor's experiments will be described below.

fil Error due to alpha rays (phenomenon that causes memory to malfunction)f! r: To prevent this, the chip surface is coated with a polymeric material such as polyimide thread synthetic resin. Since the package is sealed at around 400C, the resin decomposes due to heating.

Ht　O’F　HtOther decomposed gas? arise.

(2) As one of the die bonding methods, the conductor surface on the ceramic base is set as the Au surface, and 400C
Scrape the back side of the Si chip by heating it back and forth to make Au.
There is a method of alloying and connecting using -8i eutectic. When this Au-8i eutectic is heated, a small amount of H, 0 in the atmosphere
reacts with and releases N7.

13+ For airtight sealing, use a metal cap A u −
A u
When N2 is added to prevent the oxidation of the -Sn preform and create a reducing atmosphere, the H and dregs remain within the cavity and adversely affect the semiconductor device.

(4) Silicon nitride (Si
N) Use a membrane 1- It may be a loco. This SiN film probably has the property of trapping Hl.+51 Since the ceramic that constitutes the package is porous, it has the property of trapping H, 0, etc., which come out into the cavity after sealing. .

[Purpose of the invention]

The purpose of the present invention is to remove by easy chemical means, especially ① I, H, 0, etc., residues that give a bad impression to semiconductor elements during and after the manufacture of semiconductor devices. % ■I, YaH! An object of the present invention is to provide a semiconductor device which eliminates the problem of device malfunction due to hot carriers by removing 0's.

The foregoing and eleventh objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[Key points of the invention]

The present invention incorporates an adsorbent into the cavity of a semiconductor package to eliminate H, which has an adverse effect on semiconductor devices.
It is designed to remove defective factors such as , H, and 0 by 1°'.

[Embodiment 1] FIG. 1 shows a cerdip type semiconductor package. In the figure, 1 is a cap made of ceramic or the like, 2 is a sealing material such as low-melting glass (lead glass), and 3 is a cap made of ceramic or the like.
is a base made of ceramic or the like, 4 is a semiconductor chip on which a memory circuit, logic circuit, etc. are formed, 5 is a lead made of 42 alloy material, etc., and 6 is a connector that connects the semiconductor chip and the lead to tlL i (, ``J''). It is a wire (bonding wire).

FIG. 2 shows an example in which the present invention is applied to the cap 1 of such a cerdip type semiconductor package. 15 side 1 of cap 1 - that is, there is water volume v on the cavity side.
! Form a scribe M7 of My yarn alloy as a W agent,
Furthermore, a porous alumina layer is formed as a moisture adsorbent on a part of the surface of the scribe layer 7.The hydrogen adsorbent used in the present invention is an Mll-based alloy, for example, an alloy consisting of Mg and N1. Preferably, an alloy consisting of 1Mg and CLI is used. Other Pd metal, La
Alloys that contain hydrogen such as Co alloys.

Money may also be used. As a method for incorporating the hydrogen adsorbent into the cavity, use metallization, which is used as a technique for forming conductor patterns or patterns, or a bonoting technique in which molten metal is dropped. When forming by metallization, it is preferable to do so after firing the ceramic package.

The reason why M and 9 are mixed with Ni and Cu to form an alloy is to increase the hydrogen absorbing ability of Mll. Ni and Cu act as catalysts that promote the reaction of My adsorbing hydrogen to form Mg.H. By adjusting the mixing ratio of NLCu within the range of approximately 2% to 50%, the hydrogen adsorption time in the package can be adjusted to W1v. If it exceeds 50%, the volume of Mg is so small that sufficient adsorption cannot be achieved. Therefore, when the hydrogen adsorption time is not so important, only MI may be used in place of the 1Mg alloy. This also applies to the case where gold 8 such as Pd is used.

In addition, in order to adsorb hydrogen sufficiently, it is preferable to perform annealing (heat treatment) and activate it. Due to this.

This is because gas inherent in the ceramic and passivation film of the package is released into the cavity.

Porous alumina is preferably used as the moisture adsorbent, and can be incorporated using the botting technique. Moreover, silica or the like may be used instead of this.

When these water accumulation adsorbents and moisture adsorbents are incorporated, it is preferable that they occupy 5% or more of the cavity surface area.

Thereby, sufficient suction image quality can be ensured.

In this way, the cap is filled with hydrogen adsorbent and water (1! & 3
? : By providing an f agent, one
−120, Ht is easily removed, i.e., the third
As shown in the figure, a semiconductor chip 4 is placed and fixed on a base 3, and the output voltage of the semiconductor chip is wire-bonded to the leads 5 using a connector wire 6, and then a sealing material 2 is applied to absorb hydrogen. When sealing the cap 1 containing the agent 7 and the moisture absorbent 8 (ii+!), the error prevention resin 9 made of polyimide resin coated on the surface of the semiconductor chip 4 decomposes and becomes HtO2Ht.
Even if other decomposed gases are released, the gases in the cavity IO are adsorbed and removed by the hydrogen g, adhesive, and moisture adsorbent.

FIG. 3 shows an embodiment in which a moisture adsorbent 7 is further provided on the surface of the base 3.

[Example 2] Figure 8i￥4 shows a ceramic type semiconductor package. In the figure, 11 is a cap made of co-plated Kovar alloy, etc., and 12 is a brazing filler metal (made of Au-8N eutectic filler metal, etc.). 13 is a lead, 14 is a layered package body made of β203 ceramic, etc., 15
is metallization (wiring) made of tungsten or the like. Further, in FIG. 4, reference numeral 16 denotes a cavity, which is formed in the semiconductor package when the cap 11 is sealed with the brazing material 12. Semiconductor chips, wire bonding, etc. are omitted in Figure 4.
In a h'i AN ceramic type semiconductor package, Fig. 5 shows an example in which the present invention is used in one corner in the cavity. Semiconductor chip 1 placed inside
7 is electrically connected to the inner lead 18 by wire bonding (not shown).

In the embodiment shown in FIG.
M as a hydrogen adsorbent is placed on the bottom surface of the cavity in the lower space of the bonding wire 1 which connects 7 and the inner lead 18.
A metal thread alloy 19 is disposed, and porous alumina 21 as a hydrogen adsorbent is disposed at the stepped portion where the inner lead 18 is disposed.

Please further explain the structure of such a semiconductor package with reference to FIG. The hydrogen adsorbent 19 shown in the first embodiment is laid on the upper surface of the package body 14, and the inner thigh part 2 of the cavity is laid down.
After wire bonding the semiconductor chip 17 and the inner leads 18 with the connector wire 22, the cap 11 is sealed using the Au-8n preform 12. Stop 1~ru.

When sealing with this Au-8n preform, I-
1.

is added, but II in the cavity 16 is adsorbed and removed by the hydrogen adsorbent 19.

In the above embodiments, both the hydrogen adsorbent and the moisture adsorbent are built into the cavity.

In the present invention, only hydrogen g and adhesive may be incorporated.

〔effect〕

(Even if soft error prevention resin such as polyimide resin decomposes due to heat during sealing, the water YG adsorbent and moisture adsorbent in the cavity will adsorb this decomposed gas, so H't
, it is possible to prevent device malfunctions due to hot carriers due to the presence of HtO.

(2) Since a hydrogen adsorbent and a moisture adsorbent are provided inside the cavity, Au-8i eutectic and H
Hl released by reaction with t0, Ht added when hermetic sealing is performed using Au-Sn preform, silicon nitride film, ceramic cap, base trapped H, JPH20? It can be easily removed.

(;3) Since H,, H, and O in the cavity are easily removed, it is possible to reduce defects in semiconductor devices that are adversely affected by the presence of H,, H, and O, and the presence of Ht-HtO in q# can be reduced. This solves the problem of device malfunctions caused by hot carriers.

(4) It is effective not only during sealing but also after sealing, and can reduce defects in semiconductor devices by simple chemical means.

Although the invention has been specifically explained above based on the embodiments of the invention made by the present inventor, the present invention is not limited to the above embodiments, and can be modified in various ways without departing from the gist thereof. Needless to say.

For example, the above-mentioned hydrogen adsorbent may be mixed into the adhesive 1, ie, the AJ' paste material or the low melting point glass material, which fixes the semiconductor pellet to the package paste. Also,
It is also possible to provide the cap with a hydrogen adsorbent or water absorbent agent for fixing the pellets to a flat ceramic base having no recesses and sealing the cap. As mentioned above, package form, capacity form +
The location of the lysing agent and its formation method can be determined as necessary.

[Application field]

In the above description, the invention made by the present inventor has been mainly applied to a hermetic type package for a semiconductor device, which is the background field of application, but the present invention is not limited thereto. It can be applied to electronic component packages where the amount of moisture and hydrogen in the package is a problem due to device malfunction.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of a cerdip type semiconductor package. FIG. 2 is a sectional view of a main part showing an embodiment of the present invention. FIG. 3 is a side sectional view showing an embodiment of the present invention. FIG. 4 is a perspective view of a DILC type semiconductor package. FIG. 5 is a partially sectional plan view showing an embodiment in which the present invention is applied to the same type of package. FIG. 6 is a side sectional view showing an embodiment of the present invention. 1...Ceramic cap, 2...Low melting point glass. 3... Ceramic paste, 4... Semiconductor chip, 5
...Lead, 6...Bonding wire, 7...
Hydrogen adsorbent, 8... Moisture adsorbent, 9... Polyimide resin, 10... Cavity, 11... Cap, 1
2... Brazing material. 13...Lead, 14...Package, 15...
Gland distribution. 16... Cavity, 17... Semiconductor chip, 18
...Inner lead, 19...Hydrogen adsorbent, 20.
・Danbe. 21... Moisture adsorbent. Agent Patent Attorney Akio Takahashi (1) No. 1
Figures / Figure 2 Figure 3 Figure 4 Figure 5 Figure 4 Figure 6 Continued from page 1 0 Inventor: Masamichi Ishihara Inside Hitachi, Ltd. Device Development Center, 1450 Kamizu Honmachi, Kodaira City ■Applicant: Hitachi, Ltd. Manufacturing location: 4-6 Kanda Surugadai, Chiyoda-ku, Tokyo

Claims (1)

[Claims] 1. A conductor device characterized in that a moisture adsorbent and a hydrogen adsorbent are built into the semiconductor package cavity. 2. The hydrogen adsorbent is magnesium or an alloy of magnesium. T! conductor device. 3. The semiconductor device according to claim 2, wherein the alloy of MI is an alloy of MJI and Ni. 4.Special # where the alloy of MP is an alloy consisting of MI and Cu
The semiconductor device according to item 2 of the range of requirements [1°5, the semiconductor device according to item 1 of the range of requirements, in which the hydrogen adsorbent is Pd metal. 6. The semiconductor device according to claim 1, wherein the hydrogen adsorbent is a LaCo alloy. 7. The semiconductor device according to claim 1, wherein the moisture adsorbent is porous alumina.