JPS6058592B2 - semiconductor equipment - Google Patents

Description

[Detailed description of the invention] The present invention relates to surface stabilization of semiconductor devices.

Conventionally, in order to stabilize the surface of semiconductor elements such as diodes, transistors, and integrated circuits, a film of silicon dioxide, silicon nitride, alumina, phosphorous glass, polyimide resin, or the like has been formed on a semiconductor substrate containing the semiconductor element. Each of these membrane materials had the following problems.

(1) When inorganic compounds such as silicon dioxide, silicon nitride, alumina, and phosphorous glass are vapor-deposited, semiconductor devices are exposed to high temperatures of 700 to 900°C.

At such high temperatures, semiconductor devices experience changes in carrier recombination rate and surface state density (
1 and m are integers, and R1 is a relatively heat-resistant group such as a phenyl group or a methyl group. R2 is not particularly limited as long as it forms a crosslink between ladder-type organosilicone polymers by post-treatment such as heating, but examples thereof include the following groups.
That is, as R2, \vAIlnvAA ~■１A υノ
hydroxyalkyl group
mercaptoalkyl group
Halogenated alkyl group, aminated alkyl group, halogenated phenyl group (decreases).

The crosslinkable ladder type silicone polymer contains benzene, N
It is soluble in solvents such as -methyl-2-pyrrolidone, 1.1.1-trichloroethane, 0-dichlorobenzene, tetralin, cyclohexanone, and veratrol.

The film is formed by applying the ladder-type organosilicone polymer onto a semiconductor substrate using a spinner or the like at a temperature near room temperature, and then drying the solvent and performing a crosslinking reaction at a temperature of 100 to 350°C.

In addition, cross-linkable ladder-type organosilicone polymer membranes can be processed using photoresist and solvent etching methods for membranes that have been solvent-dried at a relatively low temperature that does not cause cross-linking reactions, and membrane materials that have undergone cross-linking reactions. This is done by a method such as plasma etching using photoresist.

The crosslinking bond obtained by heating the ladder-type organosilicone polymer is not determined depending on the type of R2, but the following bonding is presumed, for example. Cross-linkable ladder-type organosilicone polymers can be used to stabilize the surface of semiconductor devices even without cross-linking, but semiconductor devices are exposed to many types of acids, alkalis, and organic solvents during the wiring formation process and cleaning process. Therefore, crosslinking is important in order to improve the stability of the coating film against these chemicals.

For example, when a phenyl group is used in R1, the crosslinked ladder type organosilicone polymer has a molecular weight of 450 to 50 (generations).
It has heat resistance that does not cause decomposition, and has sufficient thermal resistance to heat treatment applied during the manufacturing process of integrated circuits, etc., and can be used in high-temperature atmospheres (200 to 300'C) that are normally carried out.
It can also withstand reliability tests.

Crosslinked ladder-type organosilicone polymers have excellent adhesion to semiconductor elements and metal materials, and hardly deteriorate even when left in high humidity.

The dielectric constant of crosslinked ladder-type organosilicone polymer is less than 3, which is lower than 3.8 for silicon dioxide, 6.5 for silicon nitride, and 9.0 for alumina, and it has a high degree of insulation. There is.

Therefore, it is possible to manufacture an element having insulation properties of a higher level than that of conventional semiconductor elements. The present invention will be explained below using examples.

Example 1 98 m01% of phenyltriethoxysilane and 2 m01% of γ-phenylaminopropyltriethoxysilane were thermally polymerized in diphenyl using a KOH catalyst to obtain a crosslinkable ladder-type organosilicone polymer.

A 1 wt% benzene solution of this polymer and 2
The viscosity ratio at 5°C was 1.7. As shown in FIG. 1A, a base region 2 and an emitter region 3 were formed in a silicon substrate 1, which also served as a collector region, by an impurity diffusion operation.

A cyclohexanone solution of the above polymer was applied to this surface using a spinner, and the solution was heated at 150° C. for 1 hour to dry the solvent, thereby obtaining a polymer film 4 as shown in FIG. 1B. Next, a photoresist layer 5 having windows as shown in FIG. 1C is formed above the electrode extraction openings in the collector region, base region, and emitter region. After that 1. ! ．． The polymer film was etched with 1-trichloroethane to form an electrode outlet as shown in Fig. 1D, and the photoresist layer was removed, followed by heat treatment at 350°C for 1 hour to obtain a crosslinked ladder-type organosilicone polymer film. shall be.

Furthermore, as shown in Fig. 1E and F, the vapor deposition of aluminum 6,
A photoresist 7 was formed, etched, and the photoresistor was removed to form a collector electrode 8, a collector electrode 9, and an emitter electrode 10. In the transistor formed as above, compared to the same type transistor using phosphor glass,
Reverse leakage current between collector and base was reduced by 15%. Example 2 Phenyltriethoxysilane 95n101% and γ-aminopropyltriethoxysilane in diphenyl with KOH
Polymerization was carried out by heating using a catalyst to obtain a crosslinkable ladder-type organosilicone polymer.

A 1% benzene solution of this polymer and benzene at 25°C.
The viscosity ratio was 1.5. A cyclohexanone solution of this polymer was applied onto a general MOS transistor using a spinner, and heated at 350°C for 1 hour to perform solvent drying and crosslinking reaction, forming a crosslinked ladder-type silicone polymer film with a thickness of 2 μm. .

This coating did not dissolve even after 5 minutes of ultrasonic cleaning in 1.1.1-trichloroethane. The MOS type transistor made in this way is 10.00 in 17 (generations).
Even after hours of mounting tests, the leakage current between the source and drain electrodes remained stable. In addition, a similar element was heated at 85°C.
Even after a mounting test of 10.00 Vf in a high temperature and high humidity environment of %RH, the defective rate remained below 1%.

A polyimide resin-treated MOS transistor obtained in a similar manner had stable leakage current in a 17CfC 10.0-hour mounting test, but the leakage current was stable at 80°C and 85%RHlO. The defective rate reached 20% in the OOO time mounting test.

Example 3 94m01% of phenyltriethoxysilane and 101% of tolyltriethoxysilane 6n were thermally polymerized in diphenyl using a KOH catalyst to obtain a crosslinkable ladder-type organosilicone polymer.

A 1% benzene solution of this polymer and benzene at 25°C.
The viscosity ratio was 2.0.

Figure 2 A and B show a base semiconductor integrated circuit 11 molded with resin 1.
This is a semiconductor device sealed with 2. The bonding pad 13 and the external connection lead 14 are connected by a thin metal wire 15. The polymer solution was dropped so as to cover the integrated circuit 11, the thin metal wires 15, and the external connection leads 14.
5C) CHeating was performed for 3 hours to form a crosslinkable ladder-type organosilicone film 16, and the outside thereof was further sealed with a molding resin. When this device was subjected to an operation test in an atmosphere of 85°C and 85% RH, it showed a lifespan approximately twice as long as when polyimide resin was used.Example 4 Methyltriethoxysilane 95m01% and γ- 5m01% of aminopropyltriethoxysilane was thermally polymerized in diphenyl ether using a KOH catalyst to obtain a crosslinkable ladder-type organosilicone polymer.

A 1% benzene solution of this polymer and benzene at 25°C.
The viscosity ratio was 1.4. A semiconductor/integrated circuit is mounted on a thin film circuit formed on an alumina substrate, and a cyclohexane solution of the above polymer is dropped so as to cover the semiconductor surface and the connection part with the thin film circuit.
A heat treatment was performed for 2 hours to perform solvent drying and crosslinking reaction.
This polymer coating is applied after soldering the circuit.1. :． 1-
It remained stable even after cleaning the entire circuit with trichloroethane. When this circuit was molded with a resin and subjected to a pressure water immersion test, the circuit using this polymer showed more than twice the durability as the circuit using polyimide resin.

As described above, according to the present invention, it is possible to easily stabilize the semiconductor surface with a polymer film that has excellent heat resistance, moisture resistance, solvent resistance, electrical properties, and adhesiveness.
A highly reliable semiconductor device can be obtained.

[Brief explanation of drawings]

Figures 1A to 1F show the process of providing a surface stabilizing film made of a crosslinkable lidar-type organosilicone polymer on a semiconductor substrate having a transistor and electrodes on the device, and Figure 2A shows a semiconductor integrated circuit device. Main sectional view, Figure 2B
FIG. 2 is a plan view cut away and showing the main parts of the semiconductor integrated circuit device. 1: Silicon substrate, 2: Base region, 3: Emitter region, 4: Polymer film, 5, 7: Photoresist, 6: Aluminum vapor deposited film, 8, 9, 10: Aluminum electrode, 1
1: Semiconductor integrated circuit, 12: Molded resin, 13: Bonding pad, 14: External connection lead, 15: Metal wire, 1
6: Polymer film.

Claims (1)

[Scope of Claims] 1. A semiconductor device characterized in that the resin on the semiconductor surface and its vicinity is made of a crosslinkable ladder-type organosilicone polymer. 2. The semiconductor device according to claim 1, wherein the crosslinkable ladder-type organopolysilicon polymer is represented by the following general formula. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, in the above formula, l and m are integers, R_1 is a phenyl group or methyl group, and R_2 is a group that crosslinks when heated.