Integrated circuit device and method of forming same

Abstract

Some embodiments relate to an integrated circuit (IC) device including a thin film resistor (TFR) overlying a substrate and including a first film and a second film stacked in a direction transverse to a top surface of the substrate. The first film includes a first material having a negative temperature coefficient of resistance (TCR) in a temperature range. The negative TCR causes a resistance of the first film to decrease as a temperature of the first film increases. The second film includes a second material having a positive TCR in a temperature range. The positive TCR causes the resistance of the second film to increase as the temperature of the second film increases. The embodiment of the invention also relates to a method for forming the integrated circuit device.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to integrated circuit devices and methods of forming the same. Background Art

[0002] Thin film technology has been applied to many different types of components within the context of integrated circuits (ICs). These components include transistors, capacitors, resistors, inductors, etc. For example, thin film resistors are particularly important in low resistivity, low temperature applications, such as haptic actuators, wearable devices, etc. Therefore, at such low resistivity values, an important characteristic of thin film resistors may be to provide a stable resistance value over a desired temperature range. Summary of the invention

[0003] An embodiment of the present disclosure provides an integrated circuit (IC) device, including: a thin film resistor (TFR), located on a substrate, and including a first film and a second film stacked in a direction transverse to the top surface of the substrate, wherein the first film includes a first material having a negative temperature coefficient of resistance (TCR) within a temperature range, and the negative temperature coefficient of resistance causes the resistance of the first film to decrease as the temperature of the first film increases, and the second film includes a second material having a positive temperature coefficient of resistance within the temperature range, and the positive temperature coefficient of resistance causes the resistance of the second film to increase as the temperature of the second film increases.

[0004] Another embodiment of the present disclosure provides an integrated circuit (IC) device, including: a thin film resistor (TFR) arranged in an interlayer dielectric (ILD) layer and on a barrier layer above a substrate, the thin film resistor including a plurality of films stacked in a direction extending away from the substrate, wherein the plurality of films include: a first material including a nitride of a metal, and a second material including the metal, the second material being completely disposed above or below the first material; a first conductive interconnect arranged on the thin film resistor; and a second conductive interconnect arranged on the thin film resistor and laterally separated from the first conductive interconnect.

[0005] Yet another embodiment of the present disclosure provides a method for forming an integrated circuit device, comprising: forming a first film comprising one of a first material or a second material over a substrate; forming a second film comprising the other of the first material or the second material on the first film; and etching the first film and the second film to form at least a portion of a thin film resistor (TFR) comprising the first material and the second material, wherein the first material has a negative temperature coefficient of resistance (TCR) within a temperature range, the negative temperature coefficient of resistance causing the resistance of the first material to decrease as the temperature of the first material increases, and the second material has a positive temperature coefficient of resistance within the temperature range, the positive temperature coefficient of resistance causing the resistance of the second material to increase as the temperature of the second material increases. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Aspects of the present disclosure are best understood from the following detailed description when read in conjunction with the accompanying drawings. It should be noted that, in accordance with standard practice in the industry, the various components are not drawn to scale. In fact, the dimensions of the various components may be arbitrarily increased or reduced for clarity of discussion.

[0007] Figures 1A to 1D Schematic cross-sectional views of some embodiments of thin film resistor (TFR) structures for integrated circuit (IC) devices employing materials with positive thermal coefficient of resistance (TCR) and materials with negative TCR according to the present disclosure are shown.

[0008] Figure 2 A conceptual graph of sheet resistance versus temperature associated with some embodiments of IC devices employing TFR structures having materials with positive TCRs and materials with negative TCRs according to the present disclosure is shown.

[0009] Figure 3 Cross-sectional views of some embodiments of IC devices employing TFR structures having materials with positive TCRs and materials with negative TCRs according to the present disclosure are shown.

[0010] FIG. 4A to FIG. 4D The invention and Figures 1A to 1D Cross-sectional views of some embodiments of IC devices associated with TFR structures.

[0011] FIG. 5A to FIG. 5K It is shown that according to the present disclosure, Figure 1C and Figure 4C The shown diagram is a cross-sectional view of an IC device with a TFR structure at various manufacturing stages.

[0012] Figure 6 A block diagram illustrating some embodiments of a method of forming an IC device using a TFR structure according to the present disclosure.

[0013] Fig. 7A and Figure 7B Schematic diagrams of first and second materials respectively forming a TFR structure of an IC device according to the present disclosure are shown. DETAILED DESCRIPTION

[0014] The present disclosure provides many different embodiments or examples for realizing the different features of the present disclosure. Specific examples of components and arrangements are described below to simplify the present disclosure. Of course, these are merely examples and are not intended to be limiting. For example, in the following description, forming a first component above or on a second component may include an embodiment in which the first component and the second component are directly contacted, and may also include an embodiment in which an additional component may be formed between the first component and the second component so that the first component and the second component may not be in direct contact. In addition, the present disclosure may repeat reference numbers and / or letters in various examples. This repetition is for the purpose of simplicity and clarity, and does not itself indicate the relationship between the various embodiments and / or configurations discussed.

[0015] Additionally, for ease of description, spatially relative terms such as "below," "beneath," "lower," "above," "upper," etc. may be used herein to describe the relationship of one element or component to another element or component as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein should likewise be interpreted accordingly.

[0016] The "resistivity" or ability of a material to resist electric current is sometimes characterized as volume resistivity or "bulk resistivity," denoted as ρ, with units of ohm-meter (Ω-m) or ohm-centimeter (Ω-cm). Using this volume resistivity value, the volume resistivity can be used to determine the resistance R (in ohms (Ω)) of a particular sample of material having a cross-sectional area A (e.g., a rectangular area of ​​width W and thickness t) through which current can flow and having a length L through which current can flow, using the relationship R = ρ(L / A) = ρ(L / Wt).

[0017] In the case of thin film resistors (sometimes referred to herein as TFRs), where the uniform thickness t of the resistor is significantly smaller than the width W and length L of the TFR, different resistivity measurements called "sheet resistance" or "surface resistance" (denoted as Rs and expressed in ohms per square (Ω / □)) are sometimes used to characterize the TFR. In addition, if the thickness t of the TFR is known, the bulk resistivity of the TFR can be calculated from the sheet resistance Rs by the relationship ρ=Rs×t. Furthermore, the resistance R of the TFR is R=(ρ / t)(L / W)=Rs(L / W), where the length L and width W are the two dimensions of the TFR as seen in a plan view.

[0018] Assuming that proper operation of a circuit employing a TFR depends on a stable resistance, R, of the TFR over a temperature range of interest, and that resistance, R, depends on the sheet resistance, Rs, then a stable value of the sheet resistance, Rs, over the same temperature range may be desirable. Unfortunately, such stability of the sheet resistance, Rs, may be difficult to achieve in a thin film environment, including at cryogenic values ​​(e.g., greater than or equal to -40 degrees Celsius (°C)). More specifically, a stable resistance over a certain temperature range depends on a low "temperature coefficient of resistance" (TCR) over that same range. The TCR (sometimes denoted α) specifies the rate of change of resistance or resistivity with respect to temperature, by a value that may vary with temperature.

[0019] To address these issues, the present disclosure provides some embodiments of an IC device that employs a thin film resistor (TFR) structure that includes at least two films that include two different materials. In some embodiments, the first material may have a negative TCR within a specific temperature range, and the second material may have a positive TCR within the same temperature range. Therefore, in some embodiments, a current may flow through the first material and the second material in parallel (e.g., in a direction orthogonal to the thickness of the TFR structure) so that within the same temperature range, a combined TCR that is numerically between the positive TCR and the negative TCR of the first material and the second material may be generated for the TFR structure (e.g., the combined TCR is closer to zero than the TCR of the first material or the second material). For example, the overall or combined TCR of the TFR structure including at least two films may maintain a low (e.g., close to zero) TCR value (e.g., less than about 50 parts per million per degree Celsius (ppm / °C)) within a temperature range (e.g., from about -40°C to about +125°C). Thus, using such a TFR structure (an embodiment of which is discussed in more detail below) can provide a stable sheet resistance Rs and associated resistance R over a desired temperature range, thereby facilitating desired operation of various circuits and devices. Such circuits and devices can include, but are not limited to, haptic drivers and wearable devices, as well as analog-to-digital (ADC) converters in medical devices, audio applications, and precision control and instrumentation.

[0020] Figures 1A to 1D Schematic cross-sectional views of some embodiments of TFR structures 100A to 100D (more generally, TFR structures 100) of integrated circuit (IC) devices according to the present disclosure are respectively shown, the IC devices employing one or more films of negative thermal coefficient of resistance (TCR) material 102 and one or more films of positive TCR material 104 within a specific temperature range. The resistance of the negative TCR material 102 decreases as the temperature of the one or more films (e.g., the negative TCR material) increases, while the resistance of the positive TCR material 104 increases as the temperature of the one or more films increases.

[0021] In some embodiments, the negative TCR material 102 and the positive TCR material 104 include conductive films. In some embodiments, the negative TCR material 102 may include a nitride-based material (e.g., a metal nitride such as tantalum nitride (TaN, or more generally, TaN x ), titanium nitride (TiN), etc.), and the positive TCR material 104 may include a metal (e.g., tantalum (Ta), titanium (Ti), etc.), such as an associated metal of the nitride-based material of the negative TCR material 102.

[0022] exist Figures 1A to 1D In each of the TFR structures 100, contact regions 101 (e.g., electrodes for electrically coupling the TFR structure 100 to other components of the IC device) are generally marked at or near opposite ends of the TFR structure 100. In some embodiments, the contact regions may be located at the upper or lower surface of the TFR structure 100, within one or both of the negative TCR material 102 and the positive TCR material 104, at the ends of the negative TCR material 102 and / or the positive TCR material 104, etc. Thus, in some embodiments, during operation, current may be understood to flow between the contact regions 101 (e.g., between the left and right ends of the TFR structure 100, as viewed by the reader).

[0023] In addition, Figures 1A to 1D In each of the embodiments, while the membranes comprising the negative TCR material 102 and the positive TCR material 104 are depicted as being stacked on top of each other, and therefore in contact with each other, other embodiments (such as side-by-side positioning of the membranes, in contact with each other, or separated from each other) are possible but are not explicitly discussed here in order to simplify the discussion presented below.

[0024] Due to the relationship between the membranes and / or the coupling between the membranes, the membrane including the negative TCR material 102 is electrically coupled in parallel with the membrane including the positive TCR material 104. Thus, the individual resistances of the membranes combine in parallel and produce a combined resistance that is lower than the individual resistances.

[0025] In addition, Figures 1A to 1DIn each of the figures, the film of the negative TCR material 102 and the film of the positive TCR material 104 are shown as having different thicknesses. In some embodiments, the relative thicknesses of the negative TCR material 102 and the positive TCR material 104 can affect the combined TCR of the TFR structure 100, thereby affecting the overall change in the sheet resistance Rs. More specifically, in some embodiments, a specific ratio of the total thickness of the film of the negative TCR material 102 to the total thickness of the film of the positive TCR material 104 can produce a minimum change in the sheet resistance Rs over a desired temperature range. More specifically, in some embodiments, in order to balance the relatively higher TCR amplitude of the positive TCR material 104 with the relatively lower TCR amplitude of the negative TCR material 102, a correspondingly thicker negative TCR material 102 relative to the positive TCR material 104 can be employed to minimize the combined TCR. Similarly, to balance the relatively high TCR magnitude of the negative TCR material 102 with the relatively low TCR magnitude of the positive TCR material 104, a correspondingly thicker positive TCR material 104 relative to the negative TCR material 102 may be employed to minimize the combined TCR. In some embodiments, a theoretical ratio of the TCR (e.g., average TCR) of the positive TCR material 104 to the TCR (e.g., average TCR) of the negative TCR material 102 may be used to initially estimate the ratio of the total thickness of the film of the negative TCR material 102 to the total thickness of the film of the positive TCR material 104. In some embodiments, strict application of the theoretical ratio may not produce a minimized combined TCR (e.g., due to variations in the composition and structure of the layers of the negative TCR material 102 and the positive TCR material that may occur during and / or after manufacturing). In some embodiments, the theoretical ratio may be within 20% of the actual thickness ratio, which produces a minimized combined TCR of the TFR structure 100. Thereafter, empirical testing of actual manufactured examples of the TFR structure 100 using multiple thickness ratios may be employed to determine the minimized combined TCR.

[0026] Additionally, in some embodiments, the overall sheet resistance Rs of the TFR structure 100 may be changed (e.g., while maintaining a desired thickness ratio) by changing the thickness of the negative TCR material 102 and the positive TCR material 104. More specifically, increasing the thickness may reduce the overall sheet resistance Rs of the TFR structure 100, while decreasing the thickness may increase the overall sheet resistance Rs of the TFR structure 100.

[0027] In some embodiments, assuming a positive TCR material 104 of tantalum (Ta) and a negative TCR material 102 of tantalum nitride (TaN), a ratio of a total thickness of the film of the positive TCR material 104 to a total thickness of the film of the negative TCR material 102 may be in a range from about 0.11 to about 0.22. For example, the total thickness of the film of the positive TCR material 104 may be in a range from about 50 angstroms to about 100 angstroms. The total thickness of the negative TCR material 102 film may be in the range of about to about Such a ratio range can produce a combined TCR of the TFR structure 100 of less than about 50 ppm / °C over a temperature range extending from at least about -40°C to about +125°C. More specifically, in some embodiments, the ratio of the total thickness of the film of tantalum (Ta) to the total thickness of tantalum nitride (TaN) can be in a range between about 0.10 and about 0.20, about 0.16, or other similar values. In some embodiments, the use of such a ratio can produce a combined TCR of less than about 5.7 ppm / °C.

[0028] Additionally, in some embodiments, the negative TCR material 102 (e.g., a nitride-based material as described above) may provide a range of nitrogen concentrations and / or crystal structures to promote consistent and acceptable negative TCR and low overall sheet resistance Rs. For example, in the case of tantalum nitride (TaN), the percentage of nitrogen (N) therein may be in the range of 29-32 percent (%), and the percentage of tantalum (Ta) may be 67-69%, yielding an N / Ta ratio of about 0.43 to about 0.46. Such concentrations may be confirmed, for example, by x-ray photoelectron spectroscopy (XPS) analysis. In some embodiments, higher levels of nitrogen in the tantalum nitride may increase the magnitude of the TCR of the negative TCR material 102, but may also increase the amount of diffusion of nitrogen from the tantalum nitride to the tantalum of the positive TCR material 104, thereby changing the properties of the positive TCR material 104.

[0029] Furthermore, in some embodiments, tantalum nitride (TaN) used as negative TCR material 102 may desirably have a (110) hexagonal orientation structure, as specified by Miller Index nomenclature, which may be confirmed by x-ray diffraction (XRD) analysis. More specifically, this hexagonal structure may yield a relatively low bulk resistivity of approximately 154 micro-ohm centimeters (μΩ-cm), which may make this structure more suitable for low resistance applications compared to a body-centered cubic (BCC) (200) structure (having a higher resistivity of 280-480 μΩ-cm).

[0030] Figure 1A 1 is a schematic cross-sectional view of a TFR structure 100A, the TFR structure 100A comprising a first film and a second film, the first film comprising a positive TCR material 104 within a temperature range, the second film being disposed above (e.g., on top of) the first film and comprising a negative TCR material 102 within the same temperature range. In some embodiments, the thickness of the negative TCR material 102 (e.g., in a vertical direction, such as Figure 1A100A) is significantly greater than the thickness of the positive TCR material 104. As described above, this thickness ratio can determine the amount of change in the sheet resistance Rs over a desired temperature range. Therefore, a selected ratio (e.g., estimated via the theoretical ratio described above and then possibly refined experimentally) can produce a desired minimum level of change in the sheet resistance Rs over a temperature range. In addition, in some embodiments, during the manufacturing process of an IC device employing the TFR structure 100A, the second film of negative TCR material 102 can serve as a protective barrier to oxidation and / or nitridation of the underlying first film.

[0031] Figure 1B 1 is a schematic cross-sectional view of a TFR structure 100B, which includes a first film and a second film, the first film including a negative TCR material 102, and the second film is disposed above (e.g., on top of) the first film and includes a positive TCR material 104. In some embodiments, the thickness of the negative TCR material 102 is significantly greater than the thickness of the positive TCR material 104, and may have a thickness similar to that of the positive TCR material 104. Figure 1A The ratios associated are the same ratios, which can produce a desired minimum level of variation in sheet resistance Rs over the temperature range of interest. Additionally, in some embodiments, the negative TCR material 102 used as the first film can provide adhesion between the TFR structure 100B and the dielectric layer (the TFR structure 100B can be located on top of the dielectric layer).

[0032] Figure 1C 1 is a schematic cross-sectional view of a TFR structure 100C, the TFR structure 100C including a first film including a negative TCR material 102, a second film disposed above (e.g., on top of) the first film and including a positive TCR material 104, and a third film disposed above (e.g., on top of) the second film and including the negative TCR material 102. In some embodiments, the total thickness of the negative TCR material 102 in the first film and the third film is significantly greater than the thickness of the positive TCR material 104 in the second film. In addition, in some embodiments, the ratio may be greater than Figure 1A and Figure 1B The associated ratios are the same, which can produce minimal levels of variation in sheet resistance Rs over certain temperature ranges. Furthermore, in some embodiments, the third film of negative TCR material 102 can serve as a protective barrier to oxidation and / or nitridation of the underlying second film during the manufacturing process of an IC device in which the TFR structure 100C is located. Additionally, in some embodiments, the first film of negative TCR material 102 can provide adhesion between the TFR structure 100C and a dielectric layer (the TFR structure 100C can be located on top of the dielectric layer).

[0033] Figure 1D1 is a schematic cross-sectional view of a TFR structure 100D, which includes a first film, a second film, and a third film, the first film including a positive TCR material 104, the second film disposed above (e.g., on top) the first film and including a negative TCR material 102, and the third film disposed above (e.g., on top) the second film and including a positive TCR material 104. In some embodiments, the thickness of the negative TCR material 102 in the second film is significantly greater than the total thickness of the positive TCR material 104 in the first film and the third film. In addition, in some embodiments, the ratio may be Figure 1A , Figure 1B and Figure 1C The associated ratios are the same, which can produce a minimal level of change in the sheet resistance Rs over the temperature range of interest.

[0034] Although in Figure 1A and Figure 1B Two membranes are shown in Figure 1C and Figure 1D , but four or more films may be stacked above or on top of each other in a TFR structure, with the films alternating between negative TCR material 102 and positive TCR material 104. In some embodiments, the ratio of the total thickness of the films of negative TCR material 102 to the total thickness of the films of positive TCR material 104 may determine the combined TCR of the TFR structure, which may minimize the variation in sheet resistance Rs over the temperature range of interest.

[0035] Figure 2 Conceptual graphs 200A, 200B, and 200C of sheet resistance Rs versus temperature T are shown in accordance with some embodiments of IC devices employing a TFR structure 100 having a material 104 with a positive TCR and a material 102 with a negative TCR according to the present disclosure. More specifically, graphs 200A, 200B, and 200C depict the temperature T at T, respectively. 1 To T 2 The sheet resistance Rs of the positive TCR material 104, the negative TCR material 102 and the TFR structure 100 is related to the temperature T within a temperature range of .

[0036] For example, in graph 200A, the positive TCR material 104 has an increasing sheet resistance Rs over a temperature range, while in graph 200B, the negative TCR material 102 has a decreasing sheet resistance Rs over the same temperature range. Thus, in some embodiments, the slope at each point along graphs 200A and 200B reflects the TCR of the associated point material at the particular temperature T at that point. Thus, as shown in graphs 200A and 200B, the TCR of the positive TCR material 104 and the TCR of the negative TCR material 102 may vary slightly over the temperature range of interest while remaining positive or negative because graphs 200A and 210B are shown as slightly curved rather than strictly linear. Given the higher magnitude difference in the positive TCR value reflected in graph 200A for the positive TCR material 104 relative to the negative TCR value reflected in graph 200B for the negative TCR material 102, the total thickness of the negative TCR material 102 may need to be greater than the total thickness of the positive TCR material 104, depending on some ratio based on the TCR values ​​reflected in graphs 200A and 200B, to produce a combined TCR of the TFR structure 100. The positive TCR value of the positive TCR material 104 balances the negative TCR value of the negative TCR material, such that the absolute value of the combined TCR of the TFR structure 100 is less than (e.g., closer to zero) the absolute value of the TCR of either the positive TCR material 104 or the negative TCR material 102, as shown in FIG. 1 To T 2 The nearly flat level of sheet resistance Rs of the TFR structure 100 over the temperature range is shown in Figure 200C. In some embodiments, the combined TCR of the TFR structure 100 can be almost zero. As discussed in detail above, Figures 1A to 1D 100 (e.g., a theoretical ratio based on a ratio of TCR values, which may be varied experimentally, as described above). In other embodiments, where the TCR value of the positive TCR material 104 over a temperature range is less than the TCR value of the negative TCR material 102 over the same temperature range, the total thickness of the positive TCR material 104 may be greater than the total thickness of the negative TCR material 102 to provide the TFR structure 100 with a near-zero TCR over the temperature range.

[0037] Figure 3A cross-sectional view of some embodiments of an IC device 300 employing a TFR structure 100 according to the present disclosure is shown, the TFR structure 100 having a material 104 with a positive TCR and a material 102 with a negative TCR. As shown, the IC device 300 may include a substrate 302 (e.g., a silicon substrate) that may include a plurality of doped or implanted regions 304 (e.g., n-doped regions) that may function as source-drain regions of transistors. One or more gate structures 306 and contacts 308 thereon within a dielectric layer 314 (e.g., an interlayer dielectric (ILD) layer) may be located above the substrate 302. Structures 310 (e.g., forming a metal layer) and associated vias 312 may also be located within the dielectric layer 314, some of which may be coupled to the doped regions 304. The dielectric layer 314 may include one or more dielectric materials, including, but not limited to, silicon oxide (SiO x ) (e.g., silicon oxide (SiO 2 )), silicon nitride (SiN), silicon carbide (SiC), carbon-doped silicon dioxide, silicon oxynitride, borosilicate glass (BSG), phosphosilicate glass (PSG), borophosphosilicate (BPSG), fluorosilicate glass (FSG), undoped silicate glass (USG), porous dielectric materials, etc.

[0038] An etch stop layer 316 may be disposed over the dielectric layer 314. The etch stop layer 316 may include, but is not limited to, silicon nitride (SiN), silicon carbide (SiC), or silicon carbonitride (SiCN). Figure 3 As shown, one or more additional conductive structures 310 or layers within the additional dielectric layer 314 and associated vias 312, as well as one or more additional etch stop layers 316, may be disposed over the etch stop layer 316. Such structures, as well as the TFR structure 100 described below, may occur during back-end-of-line (BEOL) processing of the IC device 300. In some embodiments, a barrier layer 318 (e.g., silicon carbide (SiC) to provide high breakdown voltage and / or temperature barrier) may be disposed over the substrate 302 and subsequent dielectric layer 314 prior to depositing materials associated with the TFR structure 100.

[0039] In some embodiments, the oxide layer 320 (eg, silicon dioxide (SiO 2 ) or another dielectric material) may be located above or on top of barrier layer 318, with oxide layer 320 serving as a non-conductive substrate for TFR structure 100 disposed thereon. Figures 1A to 1D As discussed, the TFR structure 100 may include two or more films of a negative TCR material 102 (eg, tantalum nitride (TaN), titanium nitride (TiN), etc.) and a positive TCR material 104 (eg, tantalum (Ta), titanium (Ti), etc.).

[0040] In addition, in some embodiments, an insulating film 322 (e.g., a nitride-based film, such as silicon nitride (SiN), aluminum nitride (AlN), silicon carbide (SiC), etc.) may be disposed on top of the TFR structure 100 to electrically isolate the TFR structure 100 and / or protect the TFR structure 100 from environmental factors during the manufacture of the IC device 300. In some embodiments, the thickness of the insulating film 322 may be at least 1000 Å.

[0041] The contact or via 312 may be electrically connected to the TFR structure 100 (eg, through the insulating film 322), and the contact or via 312 may serve as an electrode or terminal of the TFR structure 100 to allow current to pass therethrough. Figure 3 As shown, electrodes in the form of vias 312 may extend through insulating film 322 and through the upper surface of TFR structure 100. In some embodiments, electrodes may extend to the upper surface of TFR structure 100 and / or contact lateral ends of TFR structure 100.

[0042] Additionally, in some embodiments, oxide layer 320, TFR structure 100, insulating film 322, and via 312 may be located within another dielectric layer 314. Furthermore, in some embodiments, additional vias, such as through dielectric vias (TDVs) 311, may extend through the upper surface of IC device 300 to couple to via 312 used as an electrode of TFR structure 100. Furthermore, in some embodiments, in addition to Figure 3 Additional metallization layers of BEOL processes beyond those shown in FIG. 3 may be included in IC device 300. Furthermore, multiple TFR structures 100 may be included in one or more such metallization layers.

[0043] FIG. 4A to FIG. 4D The invention and Figures 1A to 1D FIG. 1 is a cross-sectional view of some embodiments of IC devices 300A to 300D associated with the TFR structures 100A to 100D of FIG. 1. Except for the differences of the TFR structures 100A to 100D, the rest of the IC devices 300A to 300D are similar to those described above. Figure 3 Same as those described above.

[0044] More specifically, Figure 4A As shown above, Figure 1A A cross-sectional view of an IC device 300A of the TFR structure 100A is shown, wherein a first film of a positive TCR material 104 is disposed below a second film of a negative TCR material 102 .

[0045] Figure 4B Shown includes as above combined Figure 1BA cross-sectional view of an IC device 300B of the TFR structure 100B is shown, wherein a first film of negative TCR material 102 is located below a second film of positive TCR material 104 .

[0046] Figure 4C As shown above, Figure 1C The cross-sectional view of the IC device 300C of the TFR structure 100C is shown, wherein the first film of the negative TCR material 102 is located below the second film of the positive TCR material 104 , and the second film is located below the third film of the negative TCR material 102 .

[0047] Figure 4D Shown includes as above combined Figure 1D The cross-sectional view of the IC device 300D of the TFR structure 100D is shown, wherein the first film of the positive TCR material 104 is located below the second film of the negative TCR material 102 , and the second film is located below the third film of the positive TCR material 104 .

[0048] In each of the IC devices 300A-300D, the ratio of the total thickness of the film of the negative TCR material 102 to the total thickness of the film of the positive TCR material 104 can determine the amount of change in the sheet resistance Rs over a desired temperature range. Therefore, a particular ratio can be selected that minimizes this amount of change, thereby stabilizing the sheet resistance Rs and associated resistance of the TFR structures 100A-100D over the temperature range of interest.

[0049] FIG. 5A to FIG. 5K FIG. 1 shows a TFR structure (eg, Figure 1C and Figure 4C TFR structure 100C) of an IC device (e.g., Figure 4C 300C) of some embodiments of the IC device. FIG. 5A to FIG. 5K Described as a series of actions, it will be understood that these actions are not restrictive, and in other embodiments, the order of actions within each series can be changed, and the disclosed method is also applicable to other structures. In other embodiments, some actions shown and / or described can be omitted in whole or in part.

[0050] For example, Figure 5A A substrate 302 is shown with doped regions 304 formed therein. Additionally, a dielectric layer 314 is located on top of the substrate 302, with conductive structures 310 and interconnect vias 312 formed therein, as well as gate structures 306 and associated conductive contacts 308. In some embodiments, the substrate 302 may be a p-type substrate, and the doped regions 304 may be n-doped regions. In some embodiments, continuous dielectric layers 314 may be separated by etch stop layers 316 or barrier layers 318 to protect the upper surface of the underlying dielectric layer 314. In some embodiments, Figure 5A The structure depicted in can be used as an example starting substrate on which one can begin to create a TFR structure (e.g., Figure 1C and Figure 4C Thin film processing of TFR structure 100C).

[0051] Figure 5B The oxide layer 320 (eg, silicon dioxide (SiO 2 ) or another dielectric material), the oxide layer 320 serves as a non-conductive base for the TFR structure 100C formed thereon.

[0052] FIG. 5C to FIG. 5E A TFR structure 100C (eg, Figure 4C ) are formed (e.g., deposited, such as by sputtering, evaporation, CVD or other forms of thin film deposition). More specifically, as shown Figure 5C As shown, a first film of negative TCR material 102 is formed on oxide layer 320. Thereafter, as shown Figure 5D As shown, a second film of positive TCR material 104 is formed on the first film. Then, Figure 5E In the embodiment, a third film of the negative TCR material 102 is formed on the second film. In other embodiments, other forms of TFR structures other than the TFR structure 100C may be formed on the oxide layer 320, such as the TFR structures 100A, 100B, or 100D.

[0053] Fig. 5F An insulating film 322 (e.g., a nitride-based film such as silicon nitride (SiN), aluminum nitride (AlN), silicon carbide (SiC), etc.) is shown formed (e.g., deposited, such as by sputtering, evaporation, CVD or other forms of thin film deposition) on the third film.

[0054] Figure 5G Portions of the oxide layer 320, the first film of the negative TCR material 102, the second film of the positive TCR material 104, the third film of the negative TCR material 102, and the insulating film 322 are shown removed (e.g., etched) to form the TFR structure 100C and non-conductive layers above and below the TFR structure 100C. In some embodiments, other thin film structures, such as other TFR structures, may be etched simultaneously.

[0055] Figure 5H The formation (eg, deposition) of an additional dielectric layer 314 overlying the TFR structure 100 and surrounding portions of the barrier layer 318 is shown.

[0056] Fig.5IVias 312 are shown formed (e.g., etched or trenched and subsequently deposited) in the additional dielectric layer 314, including vias 312 that serve as electrodes for the TFR structure 100C. In some embodiments, the etching or trenching of the vias 312 that serve as electrodes may extend through the insulating film 322 and to (or through) the upper surface of the third film of the negative TCR material 102. In other embodiments, the electrodes may extend further into the TFR structure 100C, including extending to and through the upper surface of the oxide layer 320.

[0057] Figure 5J Another etch stop layer 316 , another dielectric layer 314 , and another etch stop layer 316 are shown formed (eg, deposited) in sequence.

[0058] Figure 5K The formation (e.g., trenching and subsequent deposition) of a via (e.g., TDV 311) is shown such that TDV 311 extends from the upper surface of etch stop layer 316, through etch stop layer 316, another dielectric layer 314, additional etch stop layer 316, and the dielectric layer 314 thereunder to form vias 312, including vias 312 electrically contacting TFR structure 100C. Thus, in some embodiments, TFR structure 100C can be a component of a larger circuit accessible by the upper surface of IC device 300C.

[0059] Figure 6 An IC device (eg, TFR structure 100A, 100B, 100C, or 100D) including a TFR structure (eg, TFR structure 100A, 100B, 100C, or 100D) is shown in accordance with the present disclosure. Figure 4C 300C) is a block diagram of some embodiments of the method 600 of the IC device 300C). Although the method and other methods shown and / or described herein are shown as a series of actions or events, it will be understood that the present disclosure is not limited to the order or actions shown. Therefore, in some embodiments, the actions can be performed in a different order than shown, and / or can be performed simultaneously. In addition, in some embodiments, the actions or events shown can be subdivided into multiple actions or events, which can be performed at a separate time, or can be performed simultaneously with other actions or sub-actions. In some embodiments, some of the actions or events shown can be omitted, and other actions or events not shown can be included.

[0060] At act 602, a substrate (e.g., Figure 5A or Figure 5B A first film including one of a first material or a second material is formed over the structure depicted in FIG. 1 , wherein the first material has a negative TCR over a temperature range (e.g., Figures 1A to 1D The negative TCR material 102), and the second material has a positive TCR over a temperature range (e.g., Figures 1A to 1DPositive TCR material 104). Figure 5C A cross-sectional view corresponding to some embodiments of act 602 is shown.

[0061] At act 604, a second film including the other of the first material or the second material is formed on the first film. Figure 5D 604. In some embodiments, one or more additional films of alternating first and second materials may be stacked on the second film (e.g., Figure 5E The formation of the third layer is shown).

[0062] At act 606, the first film and the second film are etched to form at least a portion of a TFR structure (e.g., TFR structure 100A, 100B, 100C, or 100D) including the first material and the second material. In some embodiments where additional films are present, the etching of act 606 may also simultaneously etch the additional films to form the TFR structure and any non-conductive films (e.g., Figure 5G oxide layer 320 and insulating film 322). Figure 5G A cross-sectional view corresponding to some embodiments of act 606 is shown.

[0063] Fig. 7A and Figure 7B Schematic diagrams of a first material and a second material forming (e.g., by sputtering) a thin film resistor structure of an IC device according to the present disclosure are respectively shown, the first material having a negative TCR (e.g., negative TCR material 102) over a temperature range and the second material having a positive TCR (e.g., positive TCR material 104) over a temperature range. Fig. 7A and Figure 7B In the process chamber 701, one or more substrates 702 may be housed (e.g., via a front opening universal pod (FOUP) that may securely hold the substrates 702 in a controlled environment for transfer between machines for processing and / or measurement). In some embodiments, each substrate 702 may include a portion of an IC device (e.g., Figure 5B As shown, two or more films of alternating negative TCR material 102 and positive TCR material 104 may be formed (e.g., sputtered) on the portion of the IC device. The process chamber 701 may also include a gas inlet 706 (e.g., controlled by a valve) to allow a selected gas to flow into the process chamber 701 to facilitate the sputtering operation. Fig. 7A and Figure 7B A metal sputtering target 704 (eg, comprising tantalum (Ta), titanium (Ti), or another metal material) is also provided in the process chamber 701.

[0064] exist Fig. 7A During the sputtering operation, the reactive gas (e.g., nitrogen (N 2) gas 708) can be supplied through the gas inlet 706, wherein the material ejected from the metal sputtering target 704 (e.g., Ta, Ti, or another metal) is mixed with N 2 The gas 708 reacts to sputter the negative TCR material 102 (e.g., tantalum nitride (TaN), titanium nitride (TiN), or another nitride-based material) onto the substrate 702. For example, the sputtering operation may be performed at FIG. 5A to FIG. 5K The method is performed during the deposition of Figure 5C and Figure 5E The negative TCR material 102 is described. In some embodiments, N 2 A higher flow rate of the gas 708 may result in a higher concentration of nitrogen in the negative TCR material 102 , which may result in a higher TCR magnitude (eg, a more negative TCR value) for the negative TCR material 102 .

[0065] exist Figure 7B In the process chamber 701, an inert gas 710 (e.g., argon (Ar)) can flow into the process chamber 701 to promote the sputtering of the positive TCR material 104 (e.g., Ta, Ti, or another metal) from the metal sputtering target 704 onto the substrate 702. In some embodiments, this sputtering can occur in a vacuum rather than in the inert gas 710. For example, the sputtering operation can be performed in a vacuum chamber 701. FIG. 5A to FIG. 5K The method is performed during the deposition of Figure 5C and Figure 5E Positive TCR material 104 is described.

[0066] Thus, by alternating the presence and / or type of gas provided through gas inlet 706, Fig. 7A and Figure 7B The alternating sputtering operation shown in can result in the deposition of alternating films of the negative TCR material 102 and the positive TCR material 104 as described above. In addition, throughout the process, the same substrate 702 and metal sputtering target 704 can be maintained within the process chamber 701, thereby providing a certain level of protection for the substrate 702 from external environmental forces. In addition, in some embodiments, various sputtering parameters (e.g., voltage, processing time, etc.) can be controlled to produce a desired thickness for each film (e.g., to provide a minimum TCR within a desired temperature range for the TFR structure 100 being produced, as discussed in detail above). Moreover, in some embodiments where the last (uppermost) film of the TFR structure 100 is the negative TCR material 102, such a film can help prevent nitridation of the underlying positive TCR material 104 when the substrate 702 is transferred from the process chamber 701 to another process chamber (e.g., for subsequent deposition of the insulating film 322, the dielectric layer 314, etc.).

[0067] In some embodiments, the present disclosure provides an IC device, comprising: a thin film resistor (TFR) located above a substrate and comprising a first film and a second film stacked in a direction transverse to a top surface of the substrate, the first film comprising a first material having a negative temperature coefficient of resistance (TCR) within a temperature range, the negative TCR causing the resistance of the first film to decrease as the temperature of the first film increases, and the second film comprising a second material having a positive TCR within the temperature range, the positive TCR causing the resistance of the second film to increase as the temperature of the second film increases. In some embodiments, the TFR has a combined TCR closer to zero than the negative TCR and the positive TCR. In some embodiments, the first material comprises tantalum nitride (TaN), the second material comprises tantalum (Ta), and the ratio of the thickness of the second film to the thickness of the first film is in a range from about 0.11 to about 0.22. In some embodiments, the ratio of the thickness of the second film to the thickness of the first film can be approximately the ratio of the negative TCR of the first material to the positive TCR of the second material. In some embodiments, the ratio of the thickness of the second film to the thickness of the first film is in a range between about 0.10 and about 0.20. In some embodiments, the IC device further comprises a first electrode and a second electrode, the first electrode being located at or near the first end of the TFR and contacting the TFR; the second electrode being located at or near the second end of the TFR opposite to the first end of the TFR and contacting the TFR. In some embodiments, the first film is located above the second film and directly contacts the second film, and the first electrode and the second electrode directly contact the first film. In some embodiments, the first film is located below the second film and directly contacts the second film, and the first electrode and the second electrode directly contact the second film. In some embodiments, the TFR further comprises a third film, the third film comprises a first material, the third film is stacked with the first film and the second film in this direction, and the second film is located between the first film and the third film in this direction. In some embodiments, the TFR further comprises a third film, the third film comprises a second material, the third film is stacked with the first film and the second film in this direction, and the first film is located between the second film and the third film in this direction.

[0068] In some embodiments, the present disclosure provides another IC device, including: a thin film resistor (TFR) disposed within an interlayer dielectric (ILD) layer and on a barrier layer above a substrate, the TFR including a plurality of films stacked in a direction extending away from the substrate, the plurality of films including a first material and a second material, the first material including a nitride of a metal, the second material including a metal, the second material being disposed completely above or below the first material; a first conductive interconnect disposed on the TFR; and a second conductive interconnect disposed on the TFR and laterally spaced apart from the first conductive interconnect, and the plurality of films having a combined TCR closer to zero than the first TCR and the second TCR. In some embodiments, the TFR has a sheet resistance that varies from a value in a range of about 12 ohms / square (Ω / □) to about 16 Ω / □ over a temperature range. In some embodiments, the first material includes tantalum nitride (TaN); and the second material includes tantalum (Ta). In some embodiments, the first material includes titanium nitride (TiN); and the second material includes titanium (Ti). In some embodiments, the first material has a first temperature coefficient of resistance (TCR) within a temperature range, and the second material has a second TCR within the temperature range, the plurality of films have a combined TCR, and an absolute value of the combined TCR is less than an absolute value of the first TCR and the second TCR. In some embodiments, the IC device further comprises: an insulating film located on top of the TFR and sharing a width with the TFR, the insulating film being vertically arranged between the ILD layer and the TFR, the insulating film comprising at least one of silicon nitride (SiN), aluminum nitride (AlN), or silicon carbide (SiC).

[0069] In some embodiments, the present disclosure provides a method comprising: forming a first film including one of a first material or a second material over a substrate; forming a second film including the other of the first material or the second material on the first film; and etching the first film and the second film to form at least a portion of a thin film resistor (TFR) including the first material and the second material, the first material having a negative temperature coefficient of resistance (TCR) over a temperature range, and the second material having a positive TCR over a temperature range. In some embodiments, forming the first film comprises sputtering one of the first material or the second material in a process chamber, and forming the second film comprises sputtering the other of the first material or the second material in a process chamber. In some embodiments, sputtering the first material comprises sputtering the first material in a process chamber including nitrogen (N 2 ) gas toward the substrate, and sputtering the second material includes sputtering the metal material toward the substrate in an atmosphere including an inert gas. In some embodiments, N 2 Variation of the flow rate of the gas changes the negative TCR of the first material.

[0070] It will be understood that in this written description and in the claims that follow, the terms "first," "second," and "third," etc., are merely general identifiers used for ease of description to distinguish different elements of a figure or series of figures. By themselves, these terms do not imply any temporal order or structural proximity of these elements, and are not intended to describe corresponding elements in different illustrated embodiments and / or embodiments not shown. For example, a "first dielectric layer" described in conjunction with a first figure may not necessarily correspond to a "first dielectric layer" described in conjunction with another figure, and may not necessarily correspond to a "first dielectric layer" in an embodiment not shown.

[0071] The features of several embodiments are summarized above so that those skilled in the art can better understand aspects of the present disclosure. Those skilled in the art should understand that they can easily use the present disclosure as a basis to design or modify other processes and structures for implementing the same purpose and / or achieving the same advantages as the embodiments introduced herein. Those skilled in the art should also appreciate that such equivalent constructions do not deviate from the spirit and scope of the present disclosure, and that they can make various changes, substitutions, and modifications herein without departing from the spirit and scope of the present disclosure.

Claims

1. An integrated circuit device comprising: A thin film resistor is located on a substrate and includes a first film and a second film stacked in a direction transverse to a top surface of the substrate, wherein The first film includes a first material having a negative temperature coefficient of resistance over a temperature range, the negative temperature coefficient of resistance causing the resistance of the first film to decrease as the temperature of the first film increases, and The second film includes a second material having a positive temperature coefficient of resistance within the temperature range, the positive temperature coefficient of resistance causing the resistance of the second film to increase as the temperature of the second film increases.

2. The integrated circuit device according to claim 1, wherein: The thin film resistor has a combined temperature coefficient of resistance that is closer to zero than the negative temperature coefficient of resistance and the positive temperature coefficient of resistance.

3. The integrated circuit device according to claim 2, wherein: The first material includes tantalum nitride (TaN), The second material includes tantalum (Ta), and A ratio of a thickness of the second film to a thickness of the first film ranges from 0.11 to 0.

22.

4. The integrated circuit device according to claim 3, wherein: The ratio of the thickness of the second film to the thickness of the first film may be approximated by the ratio of the negative temperature coefficient of resistance of the first material to the positive temperature coefficient of resistance of the second material.

5. The integrated circuit device according to claim 3, wherein: A ratio of a thickness of the second film to a thickness of the first film is in a range between 0.10 and 0.

20.

6. The integrated circuit device according to claim 1, further comprising: a first electrode located at or near a first end of the thin film resistor and contacting the thin film resistor; as well as A second electrode is located at or near a second end of the thin-film resistor opposite to the first end of the thin-film resistor and contacts the thin-film resistor.

7. The integrated circuit device according to claim 6, wherein: The first film is located above and directly contacts the second film, and The first electrode and the second electrode directly contact the first film.

8. The integrated circuit device according to claim 6, wherein: The first film is located below and directly contacts the second film, and The first electrode and the second electrode directly contact the second film.

9. An integrated circuit (IC) device comprising: A thin film resistor (TFR) is arranged in an interlayer dielectric (ILD) layer and on a barrier layer above a substrate, the thin film resistor comprising a plurality of films stacked in a direction extending away from the substrate, wherein the plurality of films comprises: a first material comprising a metal nitride, and a second material, including the metal, the second material being disposed entirely above or below the first material; a first conductive interconnect disposed on the thin film resistor; and A second conductive interconnect is disposed on the thin film resistor and is laterally spaced apart from the first conductive interconnect.

10. A method of forming an integrated circuit device, comprising: forming a first film including one of a first material or a second material over a substrate; forming a second film including the other of the first material or the second material on the first film; as well as etching the first film and the second film to form at least a portion of a thin film resistor including the first material and the second material, wherein The first material has a negative temperature coefficient of resistance over a temperature range, the negative temperature coefficient of resistance causing the resistance of the first material to decrease as the temperature of the first material increases, and The second material has a positive temperature coefficient of resistance within the temperature range, the positive temperature coefficient of resistance causing the electrical resistance of the second material to increase as the temperature of the second material increases.

Images