RESISTANCE ELEMENT AND ELECTRONIC DEVICE
20220384561 · 2022-12-01
Assignee
Inventors
Cpc classification
H01L27/0676
ELECTRICITY
International classification
Abstract
A resistance element includes a resistive film, in which the resistive film is adjacent to a protrusion formed on a surface of a semiconductor substrate, the protrusion including a step traversed by the resistive film.
Claims
1. A resistance element comprising: a resistive film, wherein the resistive film is adjacent to a protrusion formed on a surface of a semiconductor substrate, the protrusion including a step traversed by the resistive film.
2. The resistance element according to claim 1, further comprising: a plurality of the resistive films connected in series.
3. The resistance element according to claim 2, wherein the plurality of the resistive films traversing the step of each of a plurality of the protrusions on the semiconductor substrate is connected in series.
4. The resistance element according to claim 3, further comprising: a protective film placed between the plurality of resistive films connected in series between the plurality of protrusions.
5. The resistance element according to claim 3, wherein two adjacent protrusions of the plurality of protrusions are placed at an interval exceeding twice a thickness of the resistive film.
6. The resistance element according to claim 1, wherein the resistive film is adjacent to the protrusion via an insulating film.
7. The resistance element according to claim 1, further comprising: an insulating layer placed on the surface of the semiconductor substrate adjacent to the protrusion, wherein the resistive film traverses a step between the insulating layer and the protrusion.
8. The resistance element according to claim 7, wherein the protrusion has a height of about 400 nm or less from the insulating layer.
9. The resistance element according to claim 1, wherein the resistive film includes polycrystalline silicon.
10. The resistance element according to claim 1, wherein the protrusion is formed by grinding a surface of the semiconductor substrate around the protrusion.
11. The resistance element according to claim 1, wherein the protrusion is formed simultaneously with a fin of a fin transistor placed on the semiconductor substrate.
12. An electronic device, comprising: a resistance element including a resistive film adjacent to a protrusion formed on a surface of a semiconductor substrate, the protrusion including a step traversed by the resistive film; and a transistor placed on the semiconductor substrate and connected to the resistance element.
Description
BRIEF DESCRIPTION OF DRAWINGS
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DESCRIPTION OF EMBODIMENTS
[0043] Next, an embodiment for implementing the present disclosure (hereinafter, referred to as “embodiment”) will be described with reference to the drawings. In the drawings, the same or similar parts are denoted by the same or similar reference numerals. Furthermore, an embodiment will be described in the following order.
[0044] 1. First embodiment
[0045] 2. Second embodiment
[0046] 3. Third embodiment
[0047] 4. Fourth embodiment
[0048] 5. Fifth embodiment
1. First Embodiment
[0049] (Configuration of Resistance Element)
[0050]
[0051] (Cross-Sectional Configuration of Resistance Element)
[0052]
[0053] The semiconductor substrate 110 is provided with the resistance element 100. The semiconductor substrate 110 includes, for example, silicon (Si). The semiconductor substrate 110 has n-type or p-type conductivity. Furthermore, the semiconductor substrate 110 may include a well region with a low impurity concentration. Still further, the semiconductor substrate 110 may include an intrinsic semiconductor.
[0054] The resistive film 140 is a film-shaped resistor including a resistive material having predetermined resistivity. The resistive film 140 is adjacent to the protrusions 111 which are to be described. Each protrusion 111 has a step 112 traversed by the resistive film 140. The semiconductor substrate 110 in
[0055] Four protrusions 111 are shown in
[0056] The protrusions 111 are regions having a protruding shape formed on the surface of the semiconductor substrate 110. Each protrusion 111 includes the same member as the semiconductor substrate 110. Each protrusion 111 is formed, for example, by grinding the surface of the semiconductor substrate 110 around a region where the protrusion 111 is to be placed.
[0057] The insulating layer 120 is placed on the surface of the semiconductor substrate 110. This insulating layer 120 is placed on the surface of the semiconductor substrate 110 excluding the protrusions 111. The protrusions 111 protrude from the insulating layer 120. The insulating layer 120 may include an insulator such as silicon oxide (SiO.sub.2) and silicon nitride (SiN). The insulating layer 120 separates the resistive film 140 from the surface of the semiconductor substrate 110 excluding the protrusions 111, which leads to reduction in parasitic capacitance of the resistance element 100.
[0058] The insulating film 130 is placed on a surface of each protrusion 111. This insulating film 130 insulates the semiconductor substrate 110 including the protrusions 111 from the resistive film 140. The insulating film 130 includes, for example, SiO.sub.2.
[0059] The protective film 150 is a film that covers the resistive film 140 and protects the resistive film 140. This protective film 150 includes, for example, an insulator such as SiN. The protective film 150 fills a gap caused in the resistive film 140 between the adjacent protrusions 111, leading to prevention of voids.
[0060] The contact plug 160 is adjacent to the resistive film 140 and connects the resistance element 100 and a wire. This contact plug 160 includes, for example, a metal such as tungsten (W) or copper (Cu). In the example shown in
[0061] The protrusions 111 are formed on the surface of the semiconductor substrate 110, and the resistive film 140 is formed to be adjacent to the protrusions 111 and across the steps 112 of the protrusions 111. Accordingly, the resistive film 140 is formed on side surfaces of the protrusions 111. Such a configuration increases an effective length of the resistive film 140 and increases a resistance of the resistive film 140. Such a configuration reduces an area occupied by the resistance element 100 on the surface of the semiconductor substrate 110.
[0062] (Method for Manufacturing Resistance Element)
[0063]
[0064] Next, a resist 302 is placed on a surface of the SiN film 301. An opening 303 is formed in a region of the resist 302 excluding a region where the protrusions 111 are to be formed (see
[0065] Next, the surfaces of the SiN film 301 and the semiconductor substrate 110 are ground using the resist 302 as a mask. The grinding is performed, for example, by anisotropic etching in which dry etching is employed. Due to this etching, the protrusions 111 are formed on the surface of the semiconductor substrate 110 (see
[0066] Next, a SiO.sub.2 film 304 is placed on the surface of the semiconductor substrate 110. The film formation is performed, for example, by CVD (see
[0067] Next, the SiO.sub.2 film 304 is ground. The grinding is performed, for example, by anisotropic etching in which dry etching is employed. Here, using the SiN film 301 as an etching stopper makes it possible to grind the SiO.sub.2 film 304 while leaving the protrusions 111 untouched. Accordingly, the insulating layer 120 is formed (see
[0068] Next, the SiN film 301 is removed by wet etching and the like, and the insulating film 130 is placed on the surfaces of the protrusions 111 protruding from the insulating layer 120. This step is performed, for example, by thermally oxidizing the semiconductor substrate 110 including the protrusions 111 (see
[0069] Next, a resistive material film 305, which is a material of the resistive film 140, is placed. This step is performed, for example, by forming a polycrystalline silicon film by CVD (see
[0070] Next, on a surface of the resistive material film 305, a resist 306 having a shape of the resistive film 140 is placed (see
[0071] Next, the resistive material film 305 is etched using the resist 306 as a mask. The etching is performed, for example, by dry etching. Accordingly, the resistive film 140 is formed (see
[0072] Next, the protective film 150 is placed. This step is performed, for example, by placing a film of an insulator such as SiN or SiO.sub.2 and etching the resistive film 140 (see
[0073] Next, an interlayer film 306 (not shown in
[0074] Next, a contact hole 307 is formed in a region of the interlayer film 306 where the contact plug 160 is to be placed. This step is performed by dry etching (see
[0075] Next, a metal serving as a material of the contact plug 160, for example, W is placed in the contact hole 307 to form the contact plug 160. This step is performed, for example, by forming a W film by CVD and removing W in portions other than the contact hole 307 (see
[0076] (Modification)
[0077] The resistance element 100 is provided with the protrusions 111 having a rectangular cross section. However, the protrusions 111 may have a different shape.
[0078] (Other Configurations of Resistance Element)
[0079]
[0080] A resistive film 140 shown in
[0081] A resistive film 140 shown in
[0082] Note that the configuration of the resistance element 100 is not limited to these examples. For example, the resistive film 140 may be placed on a protrusion 111 having a triangular or hemispherical cross section.
[0083] As described above, in the resistance element 100 according to the first embodiment of the present disclosure, the resistive film 140 is formed across the steps of the plurality of protrusions 111, which makes it possible to extend the resistive film 140 along the steps. Such a configuration increases a length of the resistive film 140 without increasing the size in the longitudinal direction. Such a configuration enables the resistive film 140 with a high resistance value and facilitates an increase in resistance of the resistance element 100.
2. Second Embodiment
[0084] In the resistance element 100 according to the first embodiment, the plurality of protrusions 111 is placed on the semiconductor substrate 110. In a second embodiment of the present disclosure, the size and the like of a protrusion 111 will be proposed.
[0085] (Cross-Sectional Configuration of Resistance Element)
[0086]
[0087] The interval w between the protrusions 111 is preferably larger than twice the thickness t1 of the resistive film 140. This is because such a configuration prevents the resistive film 140 on a side surface of a protrusion 111 between adjacent protrusions 111 from touching the resistive film 140 on the opposite side surface and prevents a decrease in resistance value.
[0088] Furthermore, the height h of the protrusion 111 from the surface of the insulating layer 120 is preferably about 400 nm or less. As described in
[0089] Other configurations of the resistance element 100 are similar to those of the resistance element 100 according to the first embodiment of the present disclosure and will not be hereinafter described.
[0090] As described above, the resistance element 100 according to the second embodiment of the present disclosure prevents a change in resistance value by defining the size of the protrusions 111 and the like.
3. Third Embodiment
[0091] In the resistance element 100 according to the first embodiment, the insulating layer 120 is placed on the surface of the semiconductor substrate 110. A third embodiment of the present disclosure is different from the first embodiment in that the insulating layer 120 is omitted.
[0092] (Cross-Sectional Configuration of Resistance Element)
[0093]
[0094] An insulating film 130 in
[0095] Other configurations of the resistance element 100 are similar to those of the resistance element 100 according to the first embodiment of the present disclosure and will not be hereinafter described.
[0096] As described above, omission of the insulating layer 120 simplifies the configuration of the resistance element 100 according to the third embodiment of the present disclosure.
4. Fourth Embodiment
[0097] The resistance element 100 according to the first embodiment is provided with the plurality of protrusions 111. A fourth embodiment of the present disclosure is different from the first embodiment in that a resistance element is provided with one protrusion 111.
[0098] (Cross-Sectional Configuration of Resistance Element)
[0099]
[0100] The resistive film 144 in
[0101] Note that the configuration of the resistance element 100 is not limited to this example. For example, both steps 112 of the protrusion 111 may be traversed by the resistive film 144. In this case, two contact plugs 161 are placed.
[0102] Other configurations of the resistance element 100 are similar to those of the resistance element 100 according to the first embodiment of the present disclosure and will not be hereinafter described.
[0103] As described above, the resistance element 100 according to the fourth embodiment of the present disclosure includes the resistive film 144 adjacent to one protrusion 111. Accordingly, it is possible to simplify the configuration of the resistance element 100.
5. Fifth Embodiment
[0104] The resistance element 100 according to the first embodiment includes the resistive film 140 that traverses the protrusions 111. In a fifth embodiment of the present disclosure, described is an electronic device that includes this resistance element 100.
[0105] (Circuit Configuration of Electronic Device)
[0106]
[0107] The gate of the MOS transistor 200 is connected to the input signal line IN, and the drain is connected to the power wire Vdd. The source of the MOS transistor 200 is connected to one end of the resistance element 100 and to the output signal line OUT. The other end of the resistance element 100 is grounded.
[0108] The electronic device 10 in
[0109] (Configuration of Electronic Device)
[0110]
[0111] The resistance element 100 in
[0112] The MOS transistor 200 is a fin transistor having one end of the protrusion 113 as a fin. This MOS transistor 200 includes a drain region 201, a gate 202, and a source region 203. The drain region 201 and the source region 203 are semiconductor regions formed in the protrusion 113 and have n-type conductivity. The gate 202 crosses over the protrusion 113 between the drain region 201 and the source region 203. A channel is formed near a surface of the protrusion 113 immediately below the gate 202. Note that
[0113] Note that thick lines in
[0114] As shown in
[0115] In this manner, since the protrusion 113 of the resistance element 100 is shared with the fin of the MOS transistor 200, it is possible to downsize the electronic device 10. Simultaneously forming the components of the resistance element 100 and the MOS transistor 200 simplifies a process for manufacturing the electronic device 10.
[0116] (Other Configurations of Electronic Device)
[0117]
[0118] The resistance element 100 in
[0119] Other configurations of the electronic device 10 are similar to those of the electronic device 10 in
[0120] As described above, since the electronic device 10 according to the fifth embodiment of the present disclosure uses the resistance element 100 and the MOS transistor 200 included in a fin transistor, the protrusion 111 and the like are shared. Accordingly, it is possible to downsize the resistance element 100 and to simplify a process for manufacturing the resistance element 100.
[0121] Lastly, the embodiments are examples of the present disclosure, and the present disclosure is not limited to the embodiments. Therefore, within the technical idea of the present disclosure, it is possible to employ various modifications of the embodiments according to designs and the like.
[0122] Furthermore, the effects described herein are for purposes of illustration and not limitation. The present disclosure may produce other effects.
[0123] Still further, the drawings in the embodiments are schematic views, and dimensional ratios and the like of each part do not always match actual ones. In addition, it is a matter of course that dimensional relations and ratios are different between drawings.
[0124] Note that the present technology also employs the following configurations.
[0125] (1) A resistance element including
[0126] a resistive film,
[0127] in which the resistive film is adjacent to a protrusion formed on a surface of a semiconductor substrate, the protrusion including a step traversed by the resistive film.
[0128] (2) The resistance element according to (1), further including a plurality of the resistive films connected in series.
[0129] (3) The resistance element according to (2), in which the plurality of the resistive films traversing the step of each of a plurality of the protrusions on the semiconductor substrate is connected in series.
[0130] (4) The resistance element according to (3), further including
[0131] a protective film placed between the plurality of resistive films connected in series between the plurality of protrusions.
[0132] (5) The resistance element according to (3) or (4), in which two adjacent protrusions of the plurality of protrusions are placed at an interval exceeding twice a thickness of the resistive film.
[0133] (6) The resistance element according to any one of (1) to (5), in which the resistive film is adjacent to the protrusion via an insulating film.
[0134] (7) The resistance element according to any one of (1) to (6), further including
[0135] an insulating layer placed on the surface of the semiconductor substrate adjacent to the protrusion,
[0136] in which the resistive film traverses a step between the insulating layer and the protrusion.
[0137] (8) The resistance element according to (7), in which the protrusion has a height of about 400 nm or less from the insulating layer.
[0138] (9) The resistance element according to any one of (1) to (8), in which the resistive film includes polycrystalline silicon.
[0139] (10) The resistance element according to any one of (1) to (9), in which the protrusion is formed by grinding a surface of the semiconductor substrate around the protrusion.
[0140] (11) The resistance element according to any one of (1) to (10), in which the protrusion is formed simultaneously with a fin of a fin transistor placed on the semiconductor substrate.
[0141] (12) An electronic device including:
[0142] a resistance element including a resistive film adjacent to a protrusion formed on a surface of a semiconductor substrate, the protrusion including a step traversed by the resistive film; and [0143] a transistor placed on the semiconductor substrate and connected to the resistance element.
[0144] It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.
REFERENCE SIGNS LIST
[0145] 10 Electronic device
[0146] 100 Resistance element
[0147] 110 Semiconductor substrate
[0148] 111, 113 Protrusion
[0149] 112 Step
[0150] 120 Insulating layer
[0151] 130 Insulating film
[0152] 140, 144 to 146 Resistive film
[0153] 150 Protective film
[0154] 160, 161 Contact plug
[0155] 200 MOS transistor