KR20050016511A - Deposition of copper films - Google Patents

Abstract

A method of forming a copper film on a substrate is disclosed. Copper films are formed by alternately adsorbing a copper-containing precursor and a reducing gas on a substrate using periodic deposition techniques. One or more of the time interval for the copper-containing precursor, the time interval for the reducing gas, and the time interval of the non-pulse may have different values during one or more deposition cycles of the periodic deposition process. Copper film formation may be compatible with integrated circuit fabrication processes. In one integrated circuit fabrication process, a copper film can be used as interconnect metallization.

Description

Deposition of Copper Films {DEPOSITION OF COPPER FILMS}

Embodiments of the present invention generally relate to a copper film deposition method, and more particularly to a copper film deposition method using a cyclical deposition technique.

Sub-quarter micron multi-level metallization is one of the key technologies for next-generation ultra-large scale integrated (VLSI) and ultra-large scale integrated (ULSI) semiconductor devices. Multilayer interconnects, the heart of this technology, require the filling of contacts, vias, lines, and other features formed with high aspect ratio openings. The reliable formation of these features is a critical issue for the success of VLSI and ULSI and for the continued efforts to improve circuit density and quality on each substrate and die.

As circuit density increases, the width of the contacts, vias, lines, and other features, as well as the width of the dielectric material therebetween, will decrease below about 250 nm (nanometers), while the thickness of the dielectric layer is substantially constant. The aspect ratio of those features, i.e., the height divided by the width, will be large. Many conventional deposition processes have difficulty filling structures when the aspect ratio exceeds 4: 1, especially when the aspect ratio exceeds 10: 1. As such, considerable effort is being made to form nanometer-sized structures having an aspect ratio with a ratio of feature height to feature width of 8: 1 or greater and void-free.

In addition, as the feature width is reduced, the device current typically remains constant or increases, which results in higher current density for those features. Elemental aluminum (AL) and its alloys have been used as conventional metals to form vias and lines in semiconductor devices, which have low electrical resistance, good adhesion to most dielectric materials, and ease of patterning. This is because it is recognized as having ease of obtaining pure aluminum, and pure aluminum. However, aluminum has a higher electrical resistance than more conductive metals such as copper (Cu), and aluminum also has the disadvantage of forming voids in the conductor by electromigration.

Copper (Cu) and its alloys are less resistant than aluminum and have significantly greater electromigration resistance than aluminum. These characteristics are important in supporting the high current densities and high device speeds that occur in high integration conditions. Copper also has good thermal conductivity. Thus, copper has been selected as the metal for filling high aspect ratio interconnect features of less than 1/4 micron on semiconductor substrates.

Although it is desirable to use copper for semiconductor device fabrication, there are limitations in selecting a manufacturing method for filling copper into high aspect ratio features of 8: 1 or higher. 1A and 1B show the results of depositing a layer of material within the high aspect ratio feature 6 on the substrate 1. The high aspect ratio feature 6 will be an opening, such as a space formed between adjacent dielectric material layers 2, such as a contact, via or trench. As shown in FIG. 1A, the copper layer 11 formed using conventional deposition techniques (eg, chemical vapor deposition (CVD), physical vapor deposition (PVD), and electroplating) may form the bottom of the feature 6. There is a tendency to deposit at a higher speed at the upper edge 6T than at the portion 6B or the side 6S, thus forming a protrusion. Overhangs or overdepositions of such materials are often referred to as crowning. Such excess material continues to accumulate on the upper edge 6T of the feature 6, closing the opening by the deposited copper layer 11 and forming voids 14 therein. Additionally, as shown in FIG. 1B, a seam 8 will be formed when the copper layer 11 deposited on both sides 6S of the feature 6 meets. The presence of voids or sutures will result in unreliable integrated circuit performance.

Thus, there is a need for a method of depositing copper into high aspect ratio structures that provide void-free and suture-free filling.

1A and 1B are cross-sectional views showing deposition results for high aspect ratio features filled using a deposition process according to the prior art.

2 is a schematic cross-sectional view of a process chamber that may be used to practice the embodiments described herein.

3 is a flowchart illustrating a process of forming a copper film using a periodic deposition technique in accordance with one embodiment described herein.

4 is a flowchart illustrating a process of forming a copper film using a periodic deposition technique in accordance with another embodiment described herein.

5A and 5B are cross-sectional views illustrating integrated circuits at different stages of the interconnect fabrication process.

A method of forming a copper film on a substrate is described. The copper film is formed by alternately adsorbing a copper-containing precursor and a reducing gas onto the substrate using periodic deposition techniques.

Copper film formation may be compatible with integrated circuit fabrication processes. In one integrated circuit fabrication process, the copper film can be used as interconnect metallization. In the case of an interconnect metallization process, a preferred process procedure includes providing a substrate having an interconnect pattern formed in one or more dielectric layers formed thereon. The interconnect pattern includes a conformally deposited barrier layer. The interconnect pattern is filled with copper (Cu) metallization by alternately adsorbing the copper-containing precursor and reducing gas onto the substrate using periodic deposition techniques.

BRIEF DESCRIPTION OF DRAWINGS To understand the above features of the present invention in more detail, the present invention, which has been briefly summarized above, is described in detail with reference to the embodiments shown in the accompanying drawings.

It is to be understood, however, that the appended drawings illustrate exemplary embodiments of the invention and are not intended to limit the scope of the invention accordingly, and that the invention may be applied to other equivalent embodiments.

2 shows a cross-sectional view of a process chamber 200 that may be used to practice the embodiments described herein. Process chamber 200 includes a substrate support 212 that is used to support substrate 210 in process chamber 200. The substrate support 212 may be moved vertically inside the process chamber 200 using the displacement mechanism 214. The substrate support may also include a vacuum chuck (not shown), an electrostatic chuck (not shown), or a clamp ring (not shown) to secure the substrate 210 during the deposition process.

Depending on the particular deposition process, substrate 210 will be heated to some intended temperature during or prior to deposition. For example, the substrate support 212 can be electrically resistively heated by applying a current from an AC power supply (not shown) to a heater element (not shown). Subsequently, the substrate 210 is heated by the substrate support 212. Instead, the substrate support may be heated using a radiant heater such as, for example, a lamp (not shown).

A vacuum pump 278 in communication with the pumping channel 279 is used to evacuate the process chamber 200 and maintain pressure within the process chamber 200. The gas supply system 230 is disposed above the process chamber 200. The gas supply system 230 provides a process gas to the process chamber 200.

The gas supply system 230 may include a chamber cover 232. Chamber cover 232 includes an expansion channel 234 extending from the center of the chamber cover 232 and a bottom surface 260 extending from the expansion channel 234 to the periphery of the chamber cover 232. The bottom surface 260 of the chamber lid 232 is sized and shaped to substantially cover the substrate 210 disposed on the substrate support 212. Expansion channel 234 also includes gas inlets 236A and 236B through which gas passes for supply.

Gas inlets 236A, 236B are connected to electronic control valves 242A, 242B, 252A, 252B. Electronic control valves 242A and 242B will be connected to process gas sources 238 and 239, respectively, and electronic control valves 252A and 252B will be connected to gas source 240. The electronically controlled valves 242A, 242B, 252A, and 252B used herein have a valve opening / closing cycle of about 1-2 seconds, more preferably less than about 0.1 seconds and can provide rapid and accurate gas flow into the process chamber 200. Refers to all control valves present. Proper control and adjustment of the gas flow to the gas supply system 230 is made by the microprocessor controller 280.

The microprocessor control unit 280 may be one of various forms of general purpose computer processors (CPUs) that can be used in industrial facilities to control various chambers and sub-processors. The computer may include any suitable memory, such as a RAM, a ROM, a floppy disk drive, a hard disk, or any other type of digital storage device, local or remote. Several support circuits may be connected to the CPU to support the processor in the usual manner. If necessary, the software routine will be stored or executed in memory by a second CPU located remotely.

When executed, the software routine converts the general purpose computer into a specific process computer that controls the chamber so that the chamber process is executed. For example, software routines may be used to precisely control the operation of the electronic control valve to execute a process procedure in accordance with embodiments described herein. Instead, software routines are executed in hardware as the operation of an application specific integrated circuit or other type of hardware, or as a combination of software or hardware.

Copper layer formation

A method of forming a copper layer on a substrate is described. Periodic deposition techniques are used to form the copper layer.

3 illustrates an embodiment of a periodic deposition process process 300 in accordance with the present invention, detailing the various steps of forming a copper layer using a constant carrier gas flow. These steps may be performed in a process chamber similar to that described above in connection with FIG. 2.

As described in step 302, a substrate is provided to a process chamber. The substrate may be, for example, a silicon substrate having an interconnect pattern formed in one or more layers of dielectric material formed thereon. For example, process chamber conditions such as temperature and pressure can be adjusted to facilitate adsorption of process gas on the substrate. In general, in the case of copper layer deposition, the process chamber should be maintained at a temperature of about 180 ° C. or less and at a pressure ranging from about 1 torr to about 10 torr.

In one embodiment where a constant carrier gas flow is desired, as described in step 304, a carrier gas stream is formed in the process chamber. The carrier gas may be selected to also act as a purge gas to remove volatile reactants and / or byproducts from the process chamber. Among the various gases, for example, a carrier gas such as helium (He), argon (Ar), and combinations thereof may be used.

Referring to step 306, after the carrier gas stream is formed in the process chamber, a pulse of copper-containing precursor is added to the carrier gas stream. The term pulse is used herein to denote a single dose of a substance added to a carrier gas stream. The pulse of the copper-containing precursor lasts for a predetermined interval.

The time interval for the pulse of the copper-containing precursor is dependent on a number of factors such as, for example, the volumetric capacity of the process chamber employed, the vacuum system connected to the chamber, and the volatility / reactivity of the reactants used. Can be changed. For example, (1) large-capacity process chambers require long pulse times because they take a long time to stabilize process conditions such as, for example, carrier purge gas flow and temperature; (2) slow process gas flow rates also require long pulse times because the process conditions take a long time to stabilize; (3) Low chamber pressure requires a long pulse time because it means that the process gas can be exhausted from the process chamber more quickly. In general, process conditions are selected such that a pulse of the copper-containing precursor provides a sufficient amount of precursor so that at least a single layer of the copper-containing precursor is adsorbed onto the substrate. Thereafter, excess copper-containing precursor remaining in the chamber will be removed from the process chamber by a constant carrier gas stream in combination with the vacuum system.

In step 308, after excess copper-containing precursor is removed from the process chamber by a constant carrier gas stream, a pulse of reducing gas is added to the carrier gas stream. The reducing gas pulse also lasts for a predetermined time interval, the duration of which is variable as described above with respect to the copper-containing precursor. In general, the time interval for the pulse of reducing gas should be long enough so that at least a single layer of reducing gas can be adsorbed onto the copper-containing precursor. Thereafter, excess reducing gas remaining in the chamber will be removed from the process chamber by the constant carrier gas stream in combination with the vacuum system.

Steps 304 to 308 include one embodiment of a deposition cycle for copper layer deposition. In the case of such an embodiment, a constant flow of carrier gas is provided into the process chamber controlled by alternating pulse periods and non-pulsing periods, the pulse periods together with the carrier gas stream and the copper-containing precursors. Alternately between reducing gases, the non-pulse period comprises only a carrier gas stream.

Each time interval for the pulses of copper-containing precursor and reducing gas may have the same duration as each other. That is, the pulse duration of the copper-containing precursor may be equal to the pulse duration of the reducing gas. In the case of such an embodiment, the time interval T ₁ for the copper-containing precursor is equal to the time interval T ₂ for the pulse of the reducing gas.

Instead, the time intervals for each of the pulses of copper-containing precursor and reducing gas may have different durations from one another. That is, the pulse duration of the copper-containing precursor may be shorter or longer than the pulse duration of the reducing gas. In the case of such an embodiment, the time interval T ₁ for the copper-containing precursor is different from the time interval T ₂ for the pulse of the reducing gas.

In addition, the non-pulse periods between the respective pulses of the copper-containing precursor and the reducing gas may have the same duration as each other. That is, the duration of the non-pulse period between each pulse of the copper-containing precursor and each pulse of the reducing gas may be the same. For such an embodiment, the non-pulse time interval T ₃ between the pulse of the copper-containing precursor and the pulse of the reducing gas is the non-pulse time interval T ₄ between the pulse of the reducing gas and the pulse of the copper-containing precursor. Same as). During the non-pulse time interval only a constant carrier gas stream is provided to the process chamber.

Instead, the non-pulse periods between the respective pulses of the copper-containing precursor and the reducing gas may have different durations from one another. That is, the duration of the non-pulse period between each pulse of the copper-containing precursor and each pulse of the reducing gas is shorter than the duration of the non-pulse period between each pulse of the reducing gas and each pulse of the copper-containing precursor or It can be long. For such an embodiment, the non-pulse time interval T ₃ between the pulse of the copper-containing precursor and the pulse of the reducing gas is the non-pulse time interval T ₄ between the pulse of the reducing gas and the pulse of the copper-containing precursor. ) During the non-pulse time interval only a constant carrier gas stream is provided to the process chamber.

In addition, the time intervals for each pulse of the copper-containing precursor and reducing gas for each cycle and the non-pulse period therebetween may have the same duration. In the case of such an embodiment, the time interval T ₁ for the pulse of the copper-containing precursor, the time interval T ₂ for the pulse of the reducing gas, the non-pulse between the pulse of the copper-containing precursor and the pulse of the reducing gas The time interval T ₃ and the non-pulse time interval T ₄ between the pulses of the reducing gas and the pulses of the copper-containing precursor each have the same value in each deposition cycle. For example, during the first deposition cycle C ₁ , the time interval T ₁ for the pulse of the copper-containing precursor is followed by the pulse of the copper-containing precursor in the subsequent deposition cycles C ₂ ... C _N. Has the same duration as the time interval T ₁ . Similarly, the duration of each pulse of reducing gas and the duration of the non-pulse between the copper-containing precursor and the pulse of reducing gas during the first deposition cycle C ₁ is subsequent to each deposition cycle C ₂ . C _N ) equals the duration of each pulse of reducing gas and the duration of non-pulse between the copper-containing precursor and the pulse of reducing gas.

Instead, the time intervals for one or more pulses of the reducing gas and the copper-containing precursor for one or more copper layer deposition cycles and the non-pulse periods therebetween may have different durations from each other. In the case of such an embodiment, one or more time intervals T ₁ for pulses of the copper-containing precursor, time intervals T ₂ for pulses of the reducing gas, the ratio between pulses of the copper-containing precursors and pulses of the reducing gas The pulse time interval T ₃ and the non-pulse time interval T ₄ between the pulse of reducing gas and the pulse of the copper-containing precursor may have different values in one or more deposition cycles of the copper deposition process. For example, during the first deposition cycle C ₁ , the time interval T ₁ for the pulse of the copper-containing precursor is followed by the pulse of the copper-containing precursor in the subsequent deposition cycles C ₂ ... C _N. It may be shorter or longer than the time interval T ₁ . Similarly, the duration of each pulse of reducing gas and the duration of the non-pulse between the copper-containing precursor and the pulse of reducing gas during the first deposition cycle C ₁ is subsequent to each deposition cycle C ₂ . C _N ) may be the same or different than the corresponding pulse duration of the reducing gas and the duration of the non-pulse between the copper-containing precursor and the pulse of the reducing gas.

Referring to step 310, after each deposition cycle (step 304 to step 308), a predetermined thickness of copper will be formed on the substrate. Depending on the specific device requirements, subsequent deposition cycles may be needed to achieve the desired thickness. In that case, steps 304 through 308 are repeated until a copper layer of the desired thickness is obtained. Thereafter, if a copper layer of the desired thickness is obtained, the process is stopped as indicated by step 212.

In another process described in connection with FIG. 4, the copper layer deposition cycle includes independent pulses for each of the copper-containing precursor, reducing gas and purge gas. For such an embodiment, the copper layer deposition process 400 includes providing a substrate to the process chamber and adjusting process chamber conditions (step 402), providing a first pulse of purge gas to the process chamber. (Step 404), providing a pulse of a copper-containing precursor to the process chamber (step 406), providing a second pulse of purge gas to the process chamber (step 408), reducing the Providing the pulses to the process chamber (step 410), and depending on whether a copper layer of the desired thickness has been obtained (step 412), repeating steps 404 to 410 or starting the deposition process. Aborting step 414 is included.

The time intervals for each of the pulses of copper-containing precursor, reducing gas and purge gas may have the same or different duration, as described above with respect to FIG. 3. Instead, the corresponding time intervals for one or more pulses of copper-containing precursor, reducing gas, and purge gas during one or more deposition cycles of the copper layer deposition process may have different durations.

In Figures 3 and 4, the copper layer deposition cycle is shown starting with a pulse of copper-containing precursor followed by a pulse of reducing gas. Instead, the copper layer cycle may begin with a pulse of reducing gas followed by a pulse of copper-containing precursor.

Copper-containing precursors include, for example, copper ⁺¹ hexafluoroacetylacetonate trimethylvinylsilane (Cu ⁺¹ (hfac) (TMVS)), copper ⁺² hexafluoroacetylacetonate (Cu ⁺² (hfac) ₂ ), Organometallic copper, such as copper ⁺¹ (β-diketonate) silolefin composite including copper ⁺² diacetylacetonate (Cu ⁺² (acac) ₂ ) and 2Cu Me ₂ NsiMe ₂ CH ₂ CH ₂ SiNMe _2, etc. It may comprise a complex. Suitable reducing gases are, for example, silane (SiH ₄ ), disilane (Si ₂ H ₆ ), dimethylsilane (SiC ₂ H ₈ ), methylsilane (SiCH ₆ ), ethylsilane (SiC ₂ H ₈ ), borane (BH ₃ ), diborane (B ₂ H ₆ ), triborane (B ₃ H ₉ ), tetraborane (B ₄ H ₁₂ ), pentaborane (B ₅ H ₁₅ ), hexaborane (B ₆ H ₁₈ ), Heptaboran (B ₇ H ₂₁ ), octaborane (B ₈ H ₂₄ ), nanoborane (B ₉ H ₂₇ ), decaborane (B ₁₀ H ₃₀ ), and the like.

One example of a copper layer deposition process is to continuously provide pulses of copper ⁺¹ hexafluoroacetylacetonate trimethylvinylsilane (Cu ⁺¹ (hfac) (TMVS)) and pulses of diborane (B ₂ H ₆ ). Include. Copper ⁺¹ hexafluoroacetylacetonate trimethylvinylsilane (Cu ⁺¹ (hfac) (TMVS)) flows from about 0.10 sccm (standard cubic centimeters per minute) to about 5 sccm, preferably from about 0.1 sccm to about 1 sccm At a rate will be supplied to a suitable flow control valve, such as an electronic control valve, and then pulsed for about 5 seconds or less, preferably about 1 second or less. Diborane (B ₂ H ₆ ) will be supplied to a suitable flow control valve, such as an electronic flow control valve, at a flow rate of about 1 sccm to about 80 sccm, preferably about 10 sccm to about 50 sccm, and then about 10 Pulsed for seconds or less, preferably about 2 seconds or less. The substrate will be maintained at a chamber pressure of about 0.1 torr to about 10 torr, preferably about 1 torr and at a temperature of about 180 ° C. or less, preferably about 120 ° C.

Another example for depositing a copper layer includes continuously providing pulses of copper ⁺¹ hexafluoroacetylacetonate trimethylvinylsilane (Cu ⁺¹ (hfac) (TMVS)) and pulses of silane (SiH ₄ ). . Copper ⁺¹ hexafluoroacetylacetonate trimethylvinylsilane (Cu ⁺¹ (hfac) (TMVS)) flows from about 0.10 sccm (standard cubic centimeters per minute) to about 5 sccm, preferably from about 0.1 sccm to about 1 sccm At a rate will be supplied to a suitable flow control valve, such as an electronic control valve, and then pulsed for about 5 seconds or less, preferably about 1 second or less. Silane (SiH ₄ ) will be supplied to a suitable flow control valve, such as an electronic flow control valve, at a flow rate of about 1 sccm to about 100 sccm, preferably about 10 sccm to about 50 sccm, and then about 10 seconds or so Or pulsed for preferably about 2 seconds or less. The substrate will be maintained at a chamber pressure of about 0.1 torr to about 10 torr, preferably about 1 torr, and at a temperature of about 180 ° C. or less, preferably about 120 ° C.

Formation of Copper Interconnect

5A and 5B are cross-sectional views showing the substrate in copper interconnect fabrication process steps with the copper layer of the present invention. 5A shows a cross-section of a substrate 500 having, for example, a metal contact 504 and a dielectric layer 502 formed thereon. The substrate 500 may include a semiconductor material such as silicon (Si), germanium (Ge), gallium arsenide (GaAs), for example. Dielectric layer 502 will include an insulating material such as, for example, silicon oxide, silicon nitride, and the like. The metal contact 504 may include, for example, copper (Cu) or the like. Opening 504H is formed in dielectric layer 502 to provide an opening over metal contact 504. Opening 504H may be formed in dielectric layer 502 using conventional lithography and etching techniques.

The barrier layer 506 will be formed in the opening 504H formed in the dielectric layer 502. The barrier layer 506 may comprise one or more refractory metal-containing layers such as, for example, titanium, titanium nitride, tantalum, tantalum nitride, tungsten, tungsten nitride, tantalum silicide nitride, titanium silicide nitride, and the like. It may include. Barrier layer 506 may be formed using a suitable deposition process. For example, titanium nitride (TiN) may be deposited from the reaction of titanium tetrachloride (TiCl ₄ ) and ammonia (NH ₃ ) using a chemical vapor deposition (CVD) process. Titanium silicide nitride (TiSiN) may be deposited by depositing titanium nitride (TiN) through thermal deposition of tetrakis (dimethylamido) titanium (TDMAT) and then exposing it to silane (SiH ₄ ).

5B, opening 504H is filled with copper metallization to complete the copper interconnect. Copper metallization is formed using the periodic deposition techniques described above with respect to FIGS. 3 and 4.

While the above description relates to preferred embodiments of the present invention, other and further embodiments of the invention will also be recognized within the scope of the invention, the scope of the invention being defined by the following claims Is determined.

Claims (68)

As a method of forming a copper layer on a substrate: (a) providing a substrate to a process chamber; And (b) forming a copper layer on the substrate using a periodic deposition process, The periodic deposition process includes a plurality of cycles, each cycle forming an inert gas flow in a process chamber and alternating exposure of the inert gas flow to one of a copper-containing precursor and a reducing gas. alternating A method of forming a copper layer comprising modulating with exposure times. The method of claim 1, wherein the exposure time to the copper-containing precursor, the exposure time to the reducing gas, the flow time of the inert gas between the exposure time to the copper-containing precursor and the exposure time to the reducing gas, and the reduction The flow time of the inert gas between the exposure time to the gas and the exposure time to the copper-containing precursor each has the same duration. The method of claim 1, wherein the exposure time to the copper-containing precursor, the exposure time to the reducing gas, the flow time of the inert gas between the exposure time to the copper-containing precursor and the exposure time to the reducing gas, and the reduction At least one of the flow time of the inert gas between the exposure time to gas and the exposure time to the copper-containing precursor has a different duration. The method of claim 1, wherein the exposure time to the copper-containing precursor during each deposition cycle of the periodic deposition process has the same duration. The method of claim 1, wherein the one or more times of exposure to the copper-containing precursor during one or more deposition cycles of the periodic deposition process have different durations. The method of claim 1, wherein the exposure time to the reducing gas during each deposition cycle of the periodic deposition process has the same duration. The method of claim 1, wherein the one or more times of exposure to the reducing gas during one or more deposition cycles of the periodic deposition process have different durations. The method of claim 1 wherein the inert gas flow time between exposure times to the copper-containing precursor and reducing gas during each deposition cycle of the periodic deposition process has the same duration. The method of claim 1, wherein one or more inert gas flow times between exposure times to the copper-containing precursor and reducing gas during each deposition cycle of the periodic deposition process have different durations. The method of claim 1 wherein the inert gas flow time between exposure times to the reducing gas and to the copper-containing precursor during each deposition cycle of the periodic deposition process has the same duration. The method of claim 1, wherein one or more inert gas flow times between exposure times to the reducing gas and to the copper-containing precursor have one or more durations during one or more deposition cycles of the periodic deposition process. The method of claim 1, wherein the copper-containing precursor is copper ⁺¹ hexafluoroacetylacetonate trimethylvinylsilane (Cu ⁺¹ (hfac) (TMVS)), copper ⁺² hexafluoroacetylacetonate (Cu ⁺² (hfac) ₂ ), copper ⁺² diacetylacetonate (Cu ⁺² (acac) ₂ ) and copper ^{+ 1} (β-diketonate) silolefin composites comprising 2Cu Me ₂ NsiMe ₂ CH ₂ CH ₂ SiNMe ₂ A copper layer forming method comprising a material selected from the group. The method of claim 1, wherein the reducing gas is silane (SiH ₄ ), disilane (Si ₂ H ₆ ), dimethylsilane (SiC ₂ H ₈ ), methylsilane (SiCH ₆ ), ethylsilane (SiC ₂ H ₈ ), Borane (BH ₃ ), Diborane (B ₂ H ₆ ), Triborane (B ₃ H ₉ ), Tetraborane (B ₄ H ₁₂ ), Pentaborane (B ₅ H ₁₅ ), Hexaborane (B ₆ H ₁₈ ) , Copper comprising one or more gases selected from the group consisting of heptaborane (B ₇ H ₂₁ ), octaborane (B ₈ H ₂₄ ), nanoborane (B ₉ H ₂₇ ), and decaborane (B ₁₀ H ₃₀ ) Layer formation method. The method of claim 1, wherein the process chamber is maintained at a temperature of less than about 180 ° C. 3. As a method of forming a copper layer on a substrate: (a) providing a substrate to a process chamber; And (b) forming a copper layer on the substrate using a periodic deposition process, The periodic deposition process includes a plurality of cycles, each cycle forming an inert gas flow in a process chamber and alternating exposure of the inert gas flow to one of a copper-containing precursor and a reducing gas. modulating the exposure times, wherein the exposure time to the copper-containing precursor, the exposure time to the reducing gas, the exposure time to the copper-containing precursor and the exposure time to the reducing gas And the flow time of the inert gas between the exposure time to the reducing gas and the exposure time to the copper-containing precursor has the same duration. 16. The method of claim 15, wherein the exposure time to the copper-containing precursor during each deposition cycle of the periodic deposition process has the same duration. The method of claim 15, wherein the one or more times of exposure to the copper-containing precursor during one or more deposition cycles of the periodic deposition process have different durations. 16. The method of claim 15, wherein the exposure time to the reducing gas during each deposition cycle of the periodic deposition process has the same duration. 16. The method of claim 15, wherein the one or more times of exposure to the reducing gas during one or more deposition cycles of the periodic deposition process have different durations. 16. The method of claim 15 wherein the inert gas flow time between exposure times to the copper-containing precursor and reducing gas during each deposition cycle of the periodic deposition process has the same duration. The method of claim 15, wherein one or more inert gas flow times between exposure times to the copper-containing precursor and reducing gas during each deposition cycle of the periodic deposition process have different durations. 16. The method of claim 15 wherein the inert gas flow time between exposure times to the reducing gas and to the copper-containing precursor during each deposition cycle of the periodic deposition process has the same duration. 16. The method of claim 15, wherein one or more inert gas flow times between exposure times to the reducing gas and the copper-containing precursor during one or more deposition cycles of the periodic deposition process have different durations. 16. The method of claim 15, wherein the copper-containing precursor is copper ⁺¹ hexafluoroacetylacetonate trimethylvinylsilane (Cu ⁺¹ (hfac) (TMVS)), copper ⁺² hexafluoroacetylacetonate (Cu ⁺² (hfac) ₂ ), copper ⁺² diacetylacetonate (Cu ⁺² (acac) ₂ ) and copper ^{+ 1} (β-diketonate) silolefin composites comprising 2Cu Me ₂ NsiMe ₂ CH ₂ CH ₂ SiNMe ₂ A copper layer forming method comprising a material selected from the group. The method of claim 15, wherein the reducing gas is silane (SiH ₄ ), disilane (Si ₂ H ₆ ), dimethylsilane (SiC ₂ H ₈ ), methylsilane (SiCH ₆ ), ethylsilane (SiC ₂ H ₈ ), Borane (BH ₃ ), Diborane (B ₂ H ₆ ), Triborane (B ₃ H ₉ ), Tetraborane (B ₄ H ₁₂ ), Pentaborane (B ₅ H ₁₅ ), Hexaborane (B ₆ H ₁₈ ) , Copper comprising one or more gases selected from the group consisting of heptaborane (B ₇ H ₂₁ ), octaborane (B ₈ H ₂₄ ), nanoborane (B ₉ H ₂₇ ), and decaborane (B ₁₀ H ₃₀ ) Layer formation method. The method of claim 15, wherein the process chamber is maintained at a temperature of less than about 180 ° C. 16. As a method of forming a copper layer on a substrate: (a) providing a substrate to a process chamber; And (b) forming a copper layer on the substrate using a periodic deposition process, The periodic deposition process includes a plurality of cycles, each cycle forming an inert gas flow in a process chamber and alternating exposure of the inert gas flow to one of a copper-containing precursor and a reducing gas. modulating the exposure times, wherein the exposure time to the copper-containing precursor, the exposure time to the reducing gas, the exposure time to the copper-containing precursor and the exposure time to the reducing gas Wherein at least one of the flow time of the inert gas and the flow time of the inert gas between the exposure time to the reducing gas and the exposure time to the copper-containing precursor has a different duration. 28. The method of claim 27, wherein the exposure time to the copper-containing precursor during each deposition cycle of the periodic deposition process has the same duration. 28. The method of claim 27, wherein one or more times of exposure to the copper-containing precursor during one or more deposition cycles of the periodic deposition process have different durations. 28. The method of claim 27, wherein the exposure time to the reducing gas during each deposition cycle of the periodic deposition process has the same duration. 28. The method of claim 27, wherein one or more times of exposure to the reducing gas during one or more deposition cycles of the periodic deposition process have different durations. 28. The method of claim 27, wherein an inert gas flow time between exposure times to the copper-containing precursor and reducing gas during each deposition cycle of the periodic deposition process has the same duration. 28. The method of claim 27, wherein one or more inert gas flow times between exposure times to the copper-containing precursor and reducing gas during each deposition cycle of the periodic deposition process have different durations. 28. The method of claim 27, wherein an inert gas flow time between exposure times to the reducing gas and the copper-containing precursor during each deposition cycle of the periodic deposition process has the same duration. 28. The method of claim 27, wherein one or more inert gas flow times between exposure times to the reducing gas and the copper-containing precursor during one or more deposition cycles of the periodic deposition process have different durations. The method of claim 27, wherein the copper-containing precursor is copper ⁺¹ hexafluoroacetylacetonate trimethylvinylsilane (Cu ⁺¹ (hfac) (TMVS)), copper ⁺² hexafluoroacetylacetonate (Cu ⁺² (hfac) ₂ ), copper ⁺² diacetylacetonate (Cu ⁺² (acac) ₂ ) and copper ^{+ 1} (β-diketonate) silolefin composites comprising 2Cu Me ₂ NsiMe ₂ CH ₂ CH ₂ SiNMe ₂ A copper layer forming method comprising a material selected from the group. The method of claim 27, wherein the reducing gas is silane (SiH ₄ ), disilane (Si ₂ H ₆ ), dimethylsilane (SiC ₂ H ₈ ), methylsilane (SiCH ₆ ), ethylsilane (SiC ₂ H ₈ ), Borane (BH ₃ ), Diborane (B ₂ H ₆ ), Triborane (B ₃ H ₉ ), Tetraborane (B ₄ H ₁₂ ), Pentaborane (B ₅ H ₁₅ ), Hexaborane (B ₆ H ₁₈ ) , Copper comprising one or more gases selected from the group consisting of heptaborane (B ₇ H ₂₁ ), octaborane (B ₈ H ₂₄ ), nanoborane (B ₉ H ₂₇ ), and decaborane (B ₁₀ H ₃₀ ) Layer formation method. 28. The method of claim 27, wherein the process chamber is maintained at a temperature of less than about 180 ° C. As a method of forming a copper layer on a substrate: (a) providing a substrate to a process chamber; And (b) forming a copper layer on the substrate using a periodic deposition process, The periodic deposition process includes a plurality of cycles, each cycle forming an inert gas flow in a process chamber and alternating exposure of the inert gas flow to one of a copper-containing precursor and a reducing gas. modulating the exposure times, wherein the exposure time to the copper-containing precursor, the exposure time to the reducing gas, the exposure time to the copper-containing precursor and the exposure time to the reducing gas Flow time of the inert gas, and the flow time of the inert gas between the exposure time to the reducing gas and the exposure time to the copper-containing precursor, each have the same duration, the exposure time to the reducing gas, the copper-containing Flow time of the inert gas between the exposure time to the precursor and the exposure time to the reducing gas, And each of the flow times of the inert gas between the exposure time to the reducing gas and the exposure time to the copper-containing precursor has the same duration during each deposition cycle of the periodic deposition process. 40. The method of claim 39, wherein the copper-containing precursor is copper ⁺¹ hexafluoroacetylacetonate trimethylvinylsilane (Cu ⁺¹ (hfac) (TMVS)), copper ⁺² hexafluoroacetylacetonate (Cu ⁺² (hfac) ₂ ), copper ⁺² diacetylacetonate (Cu ⁺² (acac) ₂ ) and copper ^{+ 1} (β-diketonate) silolefin composites comprising 2Cu Me ₂ NsiMe ₂ CH ₂ CH ₂ SiNMe ₂ A copper layer forming method comprising a material selected from the group. The method of claim 39, wherein the reducing gas is silane (SiH ₄ ), disilane (Si ₂ H ₆ ), dimethyl silane (SiC ₂ H ₈ ), methyl silane (SiCH ₆ ), ethyl silane (SiC ₂ H ₈ ), Borane (BH ₃ ), Diborane (B ₂ H ₆ ), Triborane (B ₃ H ₉ ), Tetraborane (B ₄ H ₁₂ ), Pentaborane (B ₅ H ₁₅ ), Hexaborane (B ₆ H ₁₈ ) , Copper comprising one or more gases selected from the group consisting of heptaborane (B ₇ H ₂₁ ), octaborane (B ₈ H ₂₄ ), nanoborane (B ₉ H ₂₇ ), and decaborane (B ₁₀ H ₃₀ ) Layer formation method. 40. The method of claim 39, wherein the process chamber is maintained at a temperature of less than about 180 ° C. As a method of forming a copper layer on a substrate: (a) providing a substrate to a process chamber; And (b) forming a copper layer on the substrate using a periodic deposition process, The periodic deposition process includes a plurality of cycles, each cycle forming an inert gas flow in a process chamber and alternating exposure of the inert gas flow to one of a copper-containing precursor and a reducing gas. modulating the exposure times, wherein the exposure time to the copper-containing precursor, the exposure time to the reducing gas, the exposure time to the copper-containing precursor and the exposure time to the reducing gas Flow time of the inert gas, and the flow time of the inert gas between the exposure time to the reducing gas and the exposure time to the copper-containing precursor, each have the same duration, the exposure time to the reducing gas, the copper-containing Flow time of the inert gas between the exposure time to the precursor and the exposure time to the reducing gas, And at least one of a flow time of an inert gas between the exposure time to the reducing gas and the exposure time to the copper-containing precursor has a different duration during one or more deposition cycles of the periodic deposition process. 45. The method of claim 43, wherein the copper-containing precursor is copper ⁺¹ hexafluoroacetylacetonate trimethylvinylsilane (Cu ⁺¹ (hfac) (TMVS)), copper ⁺² hexafluoroacetylacetonate (Cu ⁺² (hfac) ₂ ), copper ⁺² diacetylacetonate (Cu ⁺² (acac) ₂ ) and copper ^{+ 1} (β-diketonate) silolefin composites comprising 2Cu Me ₂ NsiMe ₂ CH ₂ CH ₂ SiNMe ₂ A copper layer forming method comprising a material selected from the group. The method of claim 43, wherein the reducing gas is silane (SiH ₄ ), disilane (Si ₂ H ₆ ), dimethylsilane (SiC ₂ H ₈ ), methylsilane (SiCH ₆ ), ethylsilane (SiC ₂ H ₈ ), Borane (BH ₃ ), Diborane (B ₂ H ₆ ), Triborane (B ₃ H ₉ ), Tetraborane (B ₄ H ₁₂ ), Pentaborane (B ₅ H ₁₅ ), Hexaborane (B ₆ H ₁₈ ) , Copper comprising one or more gases selected from the group consisting of heptaborane (B ₇ H ₂₁ ), octaborane (B ₈ H ₂₄ ), nanoborane (B ₉ H ₂₇ ), and decaborane (B ₁₀ H ₃₀ ) Layer formation method. 44. The method of claim 43, wherein the process chamber is maintained at a temperature of less than about 180 ° C. As a method of forming a copper layer on a substrate: (a) providing a substrate to a process chamber; And (b) forming a copper layer on the substrate using a periodic deposition process, The periodic deposition process includes a plurality of cycles, each cycle forming an inert gas flow in a process chamber and alternating exposure of the inert gas flow to one of a copper-containing precursor and a reducing gas. modulating the exposure times, wherein the exposure time to the copper-containing precursor, the exposure time to the reducing gas, the exposure time to the copper-containing precursor and the exposure time to the reducing gas At least one of a flow time of an inert gas and a flow time of an inert gas between the exposure time to the reducing gas and the exposure time to the copper-containing precursor has a different duration, the exposure time to the reducing gas and the copper The respective flow time of the inert gas between the exposure time to the containing precursor is A method of forming a copper layer having the same duration during each deposition cycle of the deposition process. 48. The method of claim 47, wherein the copper-containing precursor is copper ⁺¹ hexafluoroacetylacetonate trimethylvinylsilane (Cu ⁺¹ (hfac) (TMVS)), copper ⁺² hexafluoroacetylacetonate (Cu ⁺² (hfac) ₂ ), copper ⁺² diacetylacetonate (Cu ⁺² (acac) ₂ ) and copper ^{+ 1} (β-diketonate) silolefin composites comprising 2Cu Me ₂ NsiMe ₂ CH ₂ CH ₂ SiNMe ₂ A copper layer forming method comprising a material selected from the group. The method of claim 47, wherein the reducing gas is silane (SiH ₄ ), disilane (Si ₂ H ₆ ), dimethylsilane (SiC ₂ H ₈ ), methylsilane (SiCH ₆ ), ethylsilane (SiC ₂ H ₈ ), Borane (BH ₃ ), Diborane (B ₂ H ₆ ), Triborane (B ₃ H ₉ ), Tetraborane (B ₄ H ₁₂ ), Pentaborane (B ₅ H ₁₅ ), Hexaborane (B ₆ H ₁₈ ) , Copper comprising one or more gases selected from the group consisting of heptaborane (B ₇ H ₂₁ ), octaborane (B ₈ H ₂₄ ), nanoborane (B ₉ H ₂₇ ), and decaborane (B ₁₀ H ₃₀ ) Layer formation method. 48. The method of claim 47, wherein the process chamber is maintained at a temperature of less than about 180 ° C. As a method of forming a copper layer on a substrate: (a) providing a substrate to a process chamber; And (b) forming a copper layer on the substrate using a periodic deposition process, The periodic deposition process includes a plurality of cycles, each cycle forming an inert gas flow in a process chamber and alternating exposure of the inert gas flow to one of a copper-containing precursor and a reducing gas. modulating the exposure times, wherein the exposure time to the copper-containing precursor, the exposure time to the reducing gas, the exposure time to the copper-containing precursor and the exposure time to the reducing gas At least one of a flow time of an inert gas and a flow time of an inert gas between the exposure time to the reducing gas and the exposure time to the copper-containing precursor has a different duration, the exposure time to the reducing gas, the copper The presence of an inert gas between the time of exposure to the containing precursor and the time of exposure to the reducing gas. At least one of a time and a flow time of an inert gas between the exposure time to the reducing gas and the exposure time to the copper-containing precursor has a different duration during one or more deposition cycles of the periodic deposition process. . 52. The copper-containing precursor of claim 51 wherein the copper-containing precursor is copper ⁺¹ hexafluoroacetylacetonate trimethylvinylsilane (Cu ⁺¹ (hfac) (TMVS)), copper ⁺² hexafluoroacetylacetonate (Cu ⁺² (hfac) ₂ ), copper ⁺² diacetylacetonate (Cu ⁺² (acac) ₂ ) and copper ^{+ 1} (β-diketonate) silolefin composites comprising 2Cu Me ₂ NsiMe ₂ CH ₂ CH ₂ SiNMe ₂ A copper layer forming method comprising a material selected from the group. The method of claim 51, wherein the reducing gas is silane (SiH ₄ ), disilane (Si ₂ H ₆ ), dimethylsilane (SiC ₂ H ₈ ), methylsilane (SiCH ₆ ), ethylsilane (SiC ₂ H ₈ ), Borane (BH ₃ ), Diborane (B ₂ H ₆ ), Triborane (B ₃ H ₉ ), Tetraborane (B ₄ H ₁₂ ), Pentaborane (B ₅ H ₁₅ ), Hexaborane (B ₆ H ₁₈ ) , Copper comprising one or more gases selected from the group consisting of heptaborane (B ₇ H ₂₁ ), octaborane (B ₈ H ₂₄ ), nanoborane (B ₉ H ₂₇ ), and decaborane (B ₁₀ H ₃₀ ) Layer formation method. 53. The method of claim 51, wherein the process chamber is maintained at a temperature of less than about 180 ° C. As a method of forming an interconnect structure on a substrate: (a) providing a substrate to a process chamber, wherein the structure of the substrate comprises a layer of insulating material having vias formed through the electrodes; And (b) forming a copper layer on the electrode using a periodic deposition process, The periodic deposition process includes a plurality of cycles, each cycle forming an inert gas flow in a process chamber and alternating exposure of the inert gas flow to one of a copper-containing precursor and a reducing gas. alternating A method of forming a copper layer comprising modulating with exposure times. 56. The method of claim 55, wherein the exposure time to the copper-containing precursor, the exposure time to the reducing gas, the flow time of the inert gas between the exposure time to the copper-containing precursor and the exposure time to the reducing gas, and the reduction The flow time of the inert gas between the exposure time to the gas and the exposure time to the copper-containing precursor each has the same duration. 56. The method of claim 55, wherein the exposure time to the copper-containing precursor, the exposure time to the reducing gas, the flow time of the inert gas between the exposure time to the copper-containing precursor and the exposure time to the reducing gas, and the reduction At least one of the flow time of the inert gas between the exposure time to gas and the exposure time to the copper-containing precursor has a different duration. 56. The method of claim 55, wherein the exposure time to the copper-containing precursor during each deposition cycle of the periodic deposition process has the same duration. 56. The method of claim 55, wherein one or more times of exposure to the copper-containing precursor during one or more deposition cycles of the periodic deposition process have different durations. 56. The method of claim 55, wherein the exposure time to the reducing gas during each deposition cycle of the periodic deposition process has the same duration. 56. The method of claim 55, wherein the one or more times of exposure to the reducing gas during one or more deposition cycles of the periodic deposition process have different durations. 56. The method of claim 55, wherein an inert gas flow time between exposure times to the copper-containing precursor and reducing gas during each deposition cycle of the periodic deposition process has the same duration. 56. The method of claim 55, wherein one or more inert gas flow times between exposure times to the copper-containing precursor and reducing gas during each deposition cycle of the periodic deposition process have different durations. 56. The method of claim 55, wherein an inert gas flow time between exposure times to the reducing gas and to the copper-containing precursor during each deposition cycle of the periodic deposition process has the same duration. 56. The method of claim 55, wherein one or more inert gas flow times between exposure times to the reducing gas and the copper-containing precursor during one or more deposition cycles of the periodic deposition process have different durations. 56. The method of claim 55, wherein the copper-containing precursor is copper ⁺¹ hexafluoroacetylacetonate trimethylvinylsilane (Cu ⁺¹ (hfac) (TMVS)), copper ⁺² hexafluoroacetylacetonate (Cu ⁺² (hfac) ₂ ), copper ⁺² diacetylacetonate (Cu ⁺² (acac) ₂ ) and copper ^{+ 1} (β-diketonate) silolefin composites comprising 2Cu Me ₂ NsiMe ₂ CH ₂ CH ₂ SiNMe ₂ A copper layer forming method comprising a material selected from the group. The method of claim 55, wherein the reducing gas is silane (SiH ₄ ), disilane (Si ₂ H ₆ ), dimethylsilane (SiC ₂ H ₈ ), methylsilane (SiCH ₆ ), ethylsilane (SiC ₂ H ₈ ), Borane (BH ₃ ), Diborane (B ₂ H ₆ ), Triborane (B ₃ H ₉ ), Tetraborane (B ₄ H ₁₂ ), Pentaborane (B ₅ H ₁₅ ), Hexaborane (B ₆ H ₁₈ ) , Copper comprising one or more gases selected from the group consisting of heptaborane (B ₇ H ₂₁ ), octaborane (B ₈ H ₂₄ ), nanoborane (B ₉ H ₂₇ ), and decaborane (B ₁₀ H ₃₀ ) Layer formation method. 56. The method of claim 55, wherein the process chamber is maintained at a temperature of less than about 180 ° C.