JPH06244299A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To enhance a monolithic microwave integrated circuit in degree of integration by a method wherein a layer optional in dielectric constant is formed on a semiconductor substrate to serve as a microstrip. CONSTITUTION:A dielectric film 12 is deposited on a semiconductor 11, a photoresist 13 is applied thereon, and a prescribed pattern is formed through a photolithography technique. An etching process is carried out using the patterned resist 13 as a mask to pattern the dielectric film 12, and a dielectric film 14 is deposited, and a photoresist 13 is patterned. Then, an etching process is carried out using the patterned resist 13 as a mask to form a region of two different dielectric constants on the semiconductor 11. Lastly, a wiring metal 15 is vapor-deposited for the formation of a wiring pattern, and thus a microstrip is formed. By this setup, a monolithic microwave integrated circuit is improved in degree of integration.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor integrated circuit and a method for manufacturing a microstrip line.

[0002]

2. Description of the Related Art Heretofore, a waveguide or a coaxial line has been used as a microwave transmission line. As a microwave line which is much smaller than these lines, what is called a microstrip line is used. It has become very important recently. In particular, it is widely used in a microwave region monolithic semiconductor integrated circuit (hereinafter referred to as MMIC) because the degree of integration cannot be improved unless a microstrip line is used.

A conventional microstrip line forming process will be described below with reference to FIG. A photoresist 62 is applied on a ceramic plate 61 (relative permittivity of about 10) having a small dielectric loss, and a microstrip line pattern is formed by a photolithography process (FIG. 6).
(A)). Next, as shown in FIG. 6B, a metal film 63 is deposited on both surfaces of the ceramic plate 61. Finally, lift-off is performed to form the microstrip line 64 (FIG. 6C). The microstrip line thus formed is widely used because a ceramic plate having a low loss and a large relative dielectric constant has been developed.

In the MMIC, compared to a general semiconductor integrated circuit (hereinafter referred to as IC), a field effect transistor (hereinafter referred to as F
(Referred to as ET) and matching between circuit blocks is extremely important. Therefore, a method is usually used in which the matching circuit portion is provided with redundancy and the adjustment is finally performed.

A conventional matching circuit adjustment method will be described below with reference to FIG. FIG. 7A shows a matching circuit unit in the MMIC. Here, the circuit is shown by a lumped constant for simplification of description. As shown in the figure, the capacitance part is C1 to C6 and the inductance part is L
And C1 ・ C3 ・ C using laser light for adjustment
The wiring of the six parts is cut (FIG. 7B). Eventually,
The circuit shown in FIG. 7C is created as an optimum matching circuit.

[0006]

By the way, in a microstrip line formed on a ceramic plate which has been widely used conventionally, an active element such as FET must be mounted at a predetermined position after the microstrip line is formed. Therefore, there is a limit to the degree of integration of the MMIC.

Further, in the conventional adjusting method, since the inductance and capacitance of the matching circuit section are made redundant, the area of the matching circuit section becomes large, resulting in a decrease in the degree of integration of the MMIC and an increase in cost.

In view of the above conventional problems, the present invention has a microstrip line, and an object thereof is to obtain a semiconductor device having a large degree of integration as an MMIC even when an active element such as an FET is mounted. .

[0009]

In order to achieve the above object, the first means for solving the problems is to form a layer having an arbitrary dielectric constant (conductivity) on a semiconductor substrate, and etch a portion other than a predetermined portion by an etching process. A method of manufacturing a semiconductor device is described in which a microstrip line is formed on the predetermined portion after the removal.

A second problem solving means is a semiconductor device for forming a microstrip line after partially changing the thickness of a layer having a dielectric constant in the first problem solving means to an arbitrary thickness. The manufacturing method.

A third problem solving means is a method of manufacturing a semiconductor device in which a microstrip line is formed after forming a portion having two or more types of dielectric constants on a semiconductor. A fourth problem-solving means is to form a microstrip line after depositing an amorphous silicon layer on a semiconductor substrate,
A method of manufacturing a semiconductor device in which the characteristic impedance of the line portion is changed by irradiating light only on a predetermined microstrip line portion.

A fifth problem solving means is a semiconductor device in which a selective ion implantation process and an annealing process are combined to arbitrarily change the conductivity of a predetermined portion, and then a microstrip line is formed on the region. Manufacturing method.

The sixth means for solving the problem is to provide a level (hereinafter referred to as a trap) for trapping carriers in the semiconductor for a certain period of time to change the characteristic impedance of the microstrip line formed on the semiconductor surface. The method of manufacturing the device.

[0014]

According to the first means for solving the problems, since the microstrip line is formed by forming the layer having the small dielectric loss and the arbitrary dielectric constant on the semiconductor substrate, it is possible to improve the integration degree of the MMIC. .

According to the second problem solving means, the characteristic impedance of the microstrip line can be changed by arbitrarily changing the thickness of the dielectric layer. According to the third problem solving means, since the portion having two or more types of dielectric constants is formed on the semiconductor, the characteristic impedance of the microstrip line can be changed depending on the location.

According to the fourth means for solving the problems, the characteristic impedance of the microstrip line can be changed by utilizing the fact that the conductivity of amorphous silicon is largely changed by the irradiation of light. Even after the formation, the matching circuit can be adjusted.

According to the fifth means for solving the problem, the microstrip line is formed on the above-mentioned region after the selective ion implantation step and the annealing step are performed to set the conductivity of a predetermined portion, so that the MMIC can be designed. The degree of freedom is improved.

According to the sixth means for solving problems, by selecting the type of trap, it becomes possible to change the characteristic impedance between capacitive and inductive depending on the frequency of the microwave propagating through the microstrip line.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. [First Embodiment] A first method of manufacturing a semiconductor device according to the present invention.
Example 1, particularly an example of a method for manufacturing a microstrip line will be described with reference to FIGS. 1 and 2.

In this semiconductor device manufacturing method, first, referring to FIG.
As shown in (a), a dielectric film A12 is deposited on the semiconductor 11, a photoresist 13 is applied, and a predetermined pattern is formed by a photolithography process. An etching process is performed using the photoresist 13 as a mask to form a pattern of the dielectric film A12, a dielectric film B14 is deposited, and then a pattern is formed again with the photoresist 13 (FIG. 1B). Next, etching is performed using the photoresist 13 as a mask to form regions having two types of dielectric constants on the semiconductor (FIG. 1C). Finally, the wiring metal 15 is vapor-deposited to form a wiring pattern to complete the microstrip line (see FIG. 1).
(D)).

When the microstrip line formed by the above steps is viewed from above, it is as shown in FIG. 2 (a). When this line is displayed by the lumped constant,
It becomes FIG.2 (b). Here, Z1, Z2, and Z3 are characteristic impedances of a portion without a dielectric layer, ZA1 and ZA2 are characteristic impedances of a dielectric A12, and ZB1 is a characteristic impedance of a dielectric B14 portion.

In the microstrip line formed as described above, the photolithography process used in the FET manufacturing process can be directly used for forming the microstrip line, so that the degree of integration of the MMIC can be easily improved. In addition, since the characteristic impedance of the microstrip line can be easily changed by increasing the type of the dielectric film or changing the thickness thereof, the method of the present embodiment does not require changing the mask for the photolithography process. Optimal matching between FETs and circuits is possible. [Second Embodiment] Second Embodiment of Semiconductor Device Manufacturing Method of the Present Invention
Example 1, particularly an example of a method of manufacturing a matching circuit will be described with reference to FIGS.

In this semiconductor device manufacturing method, first, referring to FIG.
As shown in (a), amorphous silicon 31 is deposited on the semiconductor 11, a photoresist 13 is applied, and a pattern of the photoresist 13 is formed by a photolithography process. With the photoresist 13 as a mask,
After removing the amorphous silicon 31 by an etching process, an insulating film 32 is deposited (FIG. 3B). Finally, the wiring metal 15 is vapor-deposited to form a wiring pattern to form a microstrip line (FIG. 3C). Figure 3
A top view of the microstrip line is shown in (d). 33 in the figure is an amorphous silicon region.

Next, an example of a matching circuit using the microstrip line thus formed is shown in FIG. 4 (a). Here, the regions 41 and 42 indicate the places where light can be emitted. FIG. 4B shows a lumped constant display of the circuit when the regions 41 and 42 are not irradiated with light. Area 4
When light is irradiated to 1.42, the amorphous silicon generates a photovoltage, and the impedance of the regions 41 and 42 becomes 0. Therefore, the circuit shown in FIG. That is, a circuit having two types of characteristics can be realized with or without light.

In the matching circuit thus formed,
Since the characteristic impedance of the circuit can be easily changed depending on the presence or absence of light irradiation, optimum matching between FETs and circuits can be easily realized. Further, since the formation of the amorphous silicon layer and the formation of the pattern can be easily realized by utilizing the usual semiconductor device manufacturing process, it can be easily introduced into the MMIC manufacturing process without increasing the cost. [Third Embodiment] Third Embodiment of Manufacturing Method of Semiconductor Device of the Present Invention
Example 1, particularly an example of a method for manufacturing a microstrip line and a circuit will be described with reference to FIG.

In this semiconductor device manufacturing method, first, referring to FIG.
As shown in (a), the photoresist 1 is formed on the semiconductor 11.
3 is applied and a pattern of the photoresist 13 is formed by a photolithography process, and then ion implantation is performed to form an implantation region A51. Then, an annealing process is performed to reduce the dielectric constant of the implanted region A51. Next, using the photoresist 13 as a mask again, ion implantation is performed to form an implantation region B52 (FIG. 5).
(B)). The implantation region B52 has a high dielectric constant because the crystal lattice is broken. Finally, after depositing the insulating film 32, the wiring metal 15 is vapor-deposited to form a wiring pattern to form a microstrip line (FIG. 5).
(C)). In this microstrip line, the injection regions A and B are capacitive and
Inducible. However, if the frequency changes, the opposite may occur. Therefore, the lumped constant display of the microstrip line is shown in FIG. 5 (d). By combining the microstrip lines formed in this way, it is possible to form circuits such as an oscillation circuit and a filter using only the microstrip lines.

In the micro-split line thus formed, the characteristic impedance at any place can be easily changed by using selective ion implantation, so that the circuit can be easily realized by using only the microwave line. Also,
Since it can be easily realized by using exactly the same process as the normal semiconductor device manufacturing process, it can be easily introduced into the MMIC manufacturing process without increasing the cost.

The present invention is not limited to the above embodiments, and various modifications can be made within the scope of the present invention, and these modifications are not excluded from the scope of the present invention.

[0029]

As is clear from the description of the above embodiment,
According to the present invention, the photolithography process used in the FET manufacturing process can be used as it is for forming the microstrip line, so that the degree of integration of the MMIC can be easily improved. In addition, since the characteristic impedance of the microstrip line can be easily changed by increasing the type or thickness of the dielectric film, it is possible to optimize the matching between FETs and circuits without changing the mask for the photolithography process. Is possible.

Further, since the characteristic impedance of the circuit can be easily changed depending on the presence or absence of light irradiation, optimum matching between FETs and circuits can be easily realized. Further, since it can be easily realized by using the normal semiconductor device manufacturing process, it can be easily introduced into the MMIC manufacturing process without increasing the cost.

Further, since the characteristic impedance at an arbitrary place can be easily changed by using the selective ion implantation, the circuit can be easily realized by using only the microwave line.

[Brief description of drawings]

FIG. 1 is a manufacturing process diagram of a microstrip line according to an embodiment of the present invention.

2A is a top view of the microstrip line, and FIG. 2B is a lumped constant line diagram of the microstrip line.

FIG. 3 is a manufacturing process diagram of a matching circuit using a microstrip line according to another embodiment of the present invention.

FIG. 4 is a circuit diagram of a matching circuit using the microstrip line.

FIG. 5 is a manufacturing process diagram of a microstrip line according to another embodiment of the present invention.

FIG. 6 is a manufacturing process diagram of a conventional microstrip line.

FIG. 7 is a circuit diagram of the microstrip line.

[Explanation of symbols]

 11 Semiconductor 12 Dielectric A 13 Photoresist 14 Dielectric B 15 Wiring Metal 31 Amorphous Silicon 32 Insulating Film

Claims (10)

[Claims] 1. A layer having an arbitrary permittivity (conductivity) is formed on a semiconductor substrate on which an active element such as a field effect transistor is formed in advance, and a portion other than a predetermined portion is removed by an etching process and then the predetermined portion is formed. A method of manufacturing a semiconductor device, comprising forming a microstrip line on a portion. 2. A layer having a dielectric constant according to claim 1 is formed on a semiconductor substrate, and the thickness of the layer having a dielectric constant is changed to an arbitrary thickness by an etching process only on a predetermined portion. After that, a method of manufacturing a semiconductor device, which comprises forming a microstrip line. 3. A layer having a dielectric constant according to claim 1 is formed on a semiconductor substrate, and only a predetermined portion is removed by an etching process, and a layer having a dielectric constant other than the above-mentioned dielectric constant is formed again. A method for manufacturing a semiconductor device, characterized in that a microstrip line is formed after forming a portion having two or more types of dielectric constants and thicknesses by removing only the portion by an etching step. 4. An amorphous silicon layer is formed on a semiconductor substrate, and the amorphous silicon layer is formed on the amorphous silicon layer.
A method of manufacturing a semiconductor device, which comprises forming the microstrip line as described above. 5. The semiconductor device according to claim 4, wherein after the formation of the microstrip line, the characteristic impedance of the line portion is changed by irradiating only a predetermined microstrip line on a semiconductor substrate. Device manufacturing method. 6. The microstrip line according to claim 4 is formed on a semiconductor substrate, a matching circuit between active elements is formed by the line, and the characteristic impedance of the line portion is changed by irradiating light. A method of manufacturing a semiconductor device, characterized by performing optimum matching of a matching circuit. 7. A microstrip line is formed on a predetermined portion of a layer having a dielectric constant on a semiconductor substrate by using a selective ion implantation method, after which the dielectric constant is arbitrarily changed. Manufacturing method of semiconductor device. 8. The selective ion implantation according to claim 7 is performed two or more times, and an annealing process is performed to form a region having a high dielectric constant, and then selective ion implantation is performed again, so that the dielectric constant is smaller than that of the region. A method of manufacturing a semiconductor device, characterized in that two or more types of characteristic impedance of a microstrip line are formed by forming a region. 9. A method of manufacturing a semiconductor device, wherein a capacitive impedance and an inductive impedance are created as the two or more types of characteristic impedances according to claim 8, and these are combined to form a circuit. 10. The characteristic impedance of the microstrip line formed on the semiconductor surface is changed by providing a level for trapping carriers in the semiconductor for a certain time by ion implantation or low temperature growth of crystals. Of manufacturing a semiconductor device.