JPH05315547A - Resistance element and manufacture thereof - Google Patents

Abstract

(57) [Summary] [Object] The present invention provides a resistance element that is a constituent element of a compound semiconductor LSI having a structure in which its resistance value can be accurately matched with a design value and the resistance value after formation is stable. And a method for manufacturing the same. [Configuration] In a region including the surface of the semi-insulating GaAs substrate 1,
A part of Ga atoms forming the substrate 1 is S which is an n-type impurity.
The resistor layer 2 is an n-type active layer substituted with i atoms, and has a polarity opposite to the n-polarity obtained by substituting a part of Ga atoms constituting the substrate 1 below the resistor layer 2 with Be atoms. The barrier layer 3 is a p-type active layer, and the first electrode 4 and the second electrode 5 connected to the resistor layer 2 near both ends of the resistor layer 2 in the vertical direction. The boundary between the resistor layer 2 and the barrier layer 3 is depleted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resistance element which is a constituent element of an integrated circuit using a compound semiconductor.

[0002]

2. Description of the Related Art One of the elements constituting a large-scale integrated circuit using a compound semiconductor (hereinafter referred to as a compound semiconductor LSI) is to determine a bias voltage applied to a transistor element, and to feed back in a circuit network. There is a resistive element to determine the quantity. Conventionally, as a resistance element mounted in a compound semiconductor LSI, an n-type or p-type thin film active layer (hereinafter referred to as a resistance layer) is formed in a predetermined region of a substrate made of a semi-insulated compound semiconductor material. What is obtained by forming is known.

FIG. 3 is a structural diagram of the resistance element obtained as described above, FIG. 3 (a) is a plan view of this resistance element, and FIG. 3 (b) is a longitudinal sectional view. As shown in the figure, after the n-type or p-type impurity implantation by the ion implantation method into the semi-insulated substrate 1, the resistor layer 2 is formed in a predetermined region including the substrate surface where the impurity concentration is uniformized by the annealing method. It is formed. A first electrode 4 and a second electrode 5 are connected to both ends of the resistor layer 2, respectively, and are used for voltage application and current path. In forming the resistance element, the shape and average resistivity of the resistor layer are determined by adjusting the implantation impurity concentration, the impurity implantation energy, and the impurity implantation region to obtain the resistance element having the intended resistance value.

[0004]

The impurities in the active layer formed in the semi-insulated substrate are compound semiconductor LSIs.
It is known to diffuse in a high temperature process that occurs in the manufacturing process after annealing. Microscopically, this diffusion proceeds along the atomic planes of the atoms replaced by the impurities, but the impurities are mixed into many atomic planes, and the ions in the compound semiconductor in which the atomic planes cross the substrate surface obliquely. In case of injection,
Macroscopically, it progresses isotropically. Conventional compound semiconductor LS
In the resistance element in I, it is impossible to suppress this diffusion, and the resistance value changes as the shape of the resistor layer and the average resistivity change. This change in resistance value cannot be accurately controlled, and has appeared as an error from the designed value of the resistance value of the mounted resistance element.

The present invention has been made in order to solve the above-mentioned problems, and a compound semiconductor LSI having a stable resistance value after being formed can be formed with its resistance value accurately matching a design value. An object of the present invention is to provide a resistance element that is a constituent element and a method for manufacturing the same.

[0006]

A resistance element of the present invention is a first element formed in a predetermined region including a substrate surface which is a resistor layer.
Of the same type as the atoms replaced by the first polar type impurity that activated the resistive layer in a region including at least a deep layer part in the adjacent portion of the polar type active layer and the resistive layer in the substrate. And a second polarity type active layer having a polarity opposite to the first polarity (hereinafter referred to as a barrier layer).

According to the method of manufacturing a resistance element of the present invention, an atom of a specific species forming the compound semiconductor is replaced in the implantation region on the semi-insulating compound semiconductor substrate by the ion implantation method to obtain the first polarity. A first step of injecting a first impurity atom that exhibits type activity, and an average arrival depth distance larger than the average arrival depth distance of the first impurity implanted in the first step by the same ion implantation method. By applying such energy, a part of atoms of the same species as the atoms of the above-mentioned specific species are replaced in the implantation region, and a second polarity type activity having a polarity opposite to the first polarity is expressed. The second step of implanting impurities, and the activation of the implanted regions of the two types of impurities implanted by using the annealing method, and the resistor having the first polarity type activity in the substrate internal region including the substrate surface. Layer, resistor layer Of the substrate adjacent portion, and having a third step of forming a barrier layer having a second polarity type active region including a deep portion.

[0008]

The inventor of the present invention has conducted experiments to confirm that an impurity in which a specific species atom in a compound semiconductor is substituted has a polarity opposite to that of the polarity activated by the inclusion of the impurity, and an impurity of the same species has a different polarity. The result is that diffusion does not occur in the layer provided as a result of the substitution with or beyond the layer.

In view of the above results, according to the resistance element of the present invention, the diffusion of impurities contained in the resistance layer is suppressed in the thickness direction by the barrier layer formed in the region including the adjacent deep layer portion of the resistance layer. Therefore, the shape change of the resistor layer can be suppressed even in the energization operation in the compound semiconductor integrated circuit manufacturing process after the resistor layer is formed and in actual use, and a constant resistance value can be maintained more accurately than in the conventional case.

Further, according to the method of manufacturing the resistance element of the present invention, it is possible to stably manufacture the resistance element to which the resistance value at the time of design is accurately applied.

[0011]

Embodiments of the present invention will be described with reference to the drawings.
1 is a perspective view of a resistance element according to the first embodiment, FIG. 1 (a) is a plan view thereof, and FIG. 1 (b) is a transverse sectional view. This resistance element is a resistor layer which is an n-type active layer in which a part of Ga atoms forming the substrate 1 is replaced with Si atoms which are n-type impurities in a predetermined region including the surface of the semi-insulating GaAs substrate 1. 2, a barrier layer 3 which is a p-type active layer in which a part of Ga atoms constituting the substrate 1 are replaced with Be atoms in an adjacent deep region of the resistor layer 2, and a resistor element near both ends of the resistor layer 2. It is composed of a first electrode 4 and a second electrode 5 connected to the layer 2. The boundary portion between the resistor layer 2 and the barrier layer 3, which is in contact with the n-type active layer and the p-type active layer, is depleted.

Since the resistance element is constructed with the above-described structure, the Si atoms, which are n-type impurities in the resistor layer 2, are diffused in the vertical direction of the substrate surface where the change in resistance value is large, and the p-type active layer is diffused. The resistance value of the resistance element once formed is maintained stable thereafter.

This resistance element is manufactured by the process shown in FIG.

First, under a predetermined surface region of the semi-insulated GaAs substrate 2, ions of Si atoms, which are n-type impurities, are accelerated by an ion implantation method to accelerate energy = 50 ke.
Implantation is performed at V and implantation ion concentration = 2.0 × 10 ¹² cm ⁻² to form an n-type implantation layer 21 (hereinafter referred to as a front resistance layer) to be a resistance layer (FIG. 2A). ).

Next, by using an ion implantation method, ions of Be atoms, which are p-type impurities, are acceleration energy = 100 keV, implantation ion concentration =
Implanted at 1.0 × 10 ¹¹ cm ^-2 to form a barrier layer p
A mold injection layer 31 (hereinafter referred to as a front barrier layer) is formed (FIG. 2B).

Subsequently, annealing is performed to smooth the distribution of Si atoms substituted with Ga atoms in the pre-resistor layer 21 and the distribution of Be atoms substituted with Ga atoms in the front barrier layer 31, which is intended at the time of design. A resistor layer 2 having a shape and a resistivity and a barrier layer 3 for suppressing deformation of the resistor layer 2 in the direction perpendicular to the surface are formed. In the smoothing process, the boundary between the resistor layer 2 and the barrier layer 3 is depleted. After that, the first electrode 4 and the second electrode 5 connected to both ends of the resistor layer 2 are formed (FIG. 2C).

Next, the second embodiment will be described. The configuration diagram of the resistance element of the second embodiment is the same as that of the first embodiment, and the impurity atom species of the resistor layer 2 and the active type and the barrier layer 3 are shown.
The impurity atomic species of are different. In this resistance element, the impurity atom species of the resistor layer 2 is Be, and the active type is p-type.
The impurity atomic species of the barrier layer 3 is Si, and the active type is n type.

Since the resistance element is constructed with the above-described structure, Be atoms, which are p-type impurities in the resistor layer 2, are diffused in the direction perpendicular to the substrate surface where the change in resistance value is large, and the Be type atoms are diffused. Since it is suppressed by the barrier layer 3, the resistance value of the resistance element once formed is maintained stable thereafter, as in the first embodiment.

The manufacturing process of this resistance element is the same as the manufacturing process of the first embodiment shown in FIG. 2, and the impurity ion species to be implanted, the acceleration energy, and the concentration of implanted ions are different. When forming the pre-resistor layer 21, Be atom ions are used as acceleration energy = 10 keV, implantation ion concentration = 2.
^Implant the substrate at 0 × 10 ¹³ cm ^-2 . Also, the front barrier layer 3
1 is formed, Si atomic ions are accelerated energy = 100 keV, implantation ion concentration = 2.0 × 10 ¹¹ cm.
Inject into the substrate with ^-2 .

The present invention is not limited to the above embodiment, but various modifications can be made.

For example, the compound semiconductors used as the substrate material in the first and second embodiments may use InP or the like in addition to GaAs, and the implanted impurity species may be other than the combination of Si atoms and Be atoms. In consideration of the substrate material, etc., one set of atoms, such as a combination of Sn atom and Be atom, that substitutes the same type of atoms among the atomic species forming the compound semiconductor of the substrate material and produces different active types. You may use it. The barrier layer may be formed not only in the deep region adjacent to the resistor layer but also in the entire adjacent region.

[0022]

As described in detail above, according to the resistance element of the present invention, a constant resistance value can be accurately maintained even in the compound semiconductor LSI manufacturing process after resistance formation and the energization operation in actual use. The LSI can operate stably. Further, according to the method of manufacturing a resistance element of the present invention, it is possible to stably manufacture a resistance element to which a resistance value at the time of design is accurately applied, and further, a compound semiconductor LSI
Can improve the quality of.

[Brief description of drawings]

1A and 1B are a plan view and a cross-sectional view of a resistance element according to a first exemplary embodiment.

FIG. 2 is a manufacturing process diagram of the resistance element shown in FIG.

FIG. 3 is a plan view and a cross-sectional view of a conventional resistance element.

[Explanation of symbols]

1 ... Semi-insulating compound semiconductor substrate, 2 ... Resistor layer, 21 ...
Front resistor layer, 3 ... Barrier layer, 31 ... Front barrier layer, 4 ... First electrode, 5 ... Second electrode.

Claims (2)

[Claims] 1. In a first region including a surface of a substrate made of a semi-insulating compound semiconductor material, a part of atoms of a specific species constituting the compound semiconductor is replaced with a first impurity atom. A first layer having a first polarity-type activity and a second region including at least a deep layer portion of the first region in a region in the substrate adjacent to the first region. At the inner,
A second layer having a second polar type activity, which is formed by replacing a part of atoms of the same kind as the atoms of the specific kind with a second impurity atom; element. 2. A substrate, which is made of a semi-insulated compound semiconductor, is replaced with an atom of a specific species constituting the compound semiconductor in an implantation region by an ion implantation method to develop a first polar type activity. A first step of injecting one impurity atom, and targeting a substrate surface region including the substrate surface region in which the first impurity is implanted into the substrate by an ion implantation method, in the implantation region A second impurity that replaces a part of the atom of the same species as the atom and causes the second polar type activity to be expressed, with the energy such that the average arrival depth is larger than the average arrival depth of the first impurity. 2. The method for manufacturing a resistance element, comprising: the step 2); and a third step of activating an implantation region of the two kinds of impurities in the substrate by an annealing method.