KR102122612B1 - Conformal doping via plasma activated atomic layer deposition and conformal film deposition - Google Patents

Abstract

Methods of doping a patterned substrate in a reaction chamber are disclosed herein. The methods may include forming a first conformal film layer having a dopant source comprising a dopant, and driving a portion of the dopant into the substrate to form a conformal doping profile. In some embodiments, forming the first film layer includes introducing a dopant precursor into the reaction chamber, adsorbing the dopant precursor under conditions to form the adsorption limiting layer, and forming a dopant source. And reacting the adsorbed dopant precursor. In addition, the apparatus for doping the substrate may include a controller having a reaction chamber, a gas inlet, and machine readable code, the controller having instructions to operate the gas inlet to introduce and adsorb the dopant precursor, and Disclosed herein are devices for doping the substrate, including instructions for reacting the adsorbed dopant precursor to form a film layer containing a dopant source.

Description

CONFORMAL DOPING VIA PLASMA ACTIVATED ATOMIC LAYER DEPOSITION AND CONFORMAL FILM DEPOSITION through plasma activated atomic layer deposition and conformal membrane deposition

Currently, there is considerable interest in three-dimensional (3D) transistor structures such as multi-gate FinFET and 3D memory devices. Some examples of 3D structures are “Tri-gate,” by J. Kavalieros (Intel), Symp. VLSI Tech, p. 50 (2006) and “Opportunities and Challenges of FinFET as a Device Structure Candidate for 14nm Node CMOS Technology,” ECS Transactions, Vol. 34, Issue 1, pp. 81-86 (2011), both of which are incorporated herein by reference for all and all purposes. Advanced 3D gate structures are employed at 22 nm technology nodes and are likely to be employed at other technology nodes with feature sizes below 22 nm. Transistors with 3D gate structures typically employ source and drain regions formed in thin vertical structures. These vertical structures are difficult to do with conventional ion implantation techniques, plasma doping techniques, and, in general, techniques involving transport of ions under an electric field. The difficulty is generally evident when doping the sidewalls, especially in high aspect ratio structures.

Thus, the ion implantation processes are usually directional, and they have many gate architecture designs, such as 3D gate designs and/or closely spaced fins that may require doping on lateral and vertical surfaces. It tends to be unsuitable for the manufacture of gate architectures. If an attempt is made to use ion implantation to dop these surfaces, such as by changing the implant tilt angle, this is particularly in the dopant dose retention and diffusion range, especially on sidewalls. It can lead to considerable variability. Frequently, in a dense array of i3D structures, there may be shadowing effects on the directional ion beam in the injector, which creates serious dose retention problems for the inclined implant angle. In addition, plasma doping techniques have recently received attention. However, there appear to be two main drawbacks to this technique. (a) it may result in simultaneous sputter erosion, which may be due to high energy ions in the plasma, (b) dopant dose and conformity ions in the plasma It seems to be sensitively dependent on the ratio of to radical density, which leads to difficulties in process control. Thus, there remains a need for better doping methods that may be used to manufacture many current gate architecture designs.

Methods of doping a patterned substrate in a reaction chamber are disclosed herein. In some embodiments, the present methods directly comprise a first conformal film comprising a dopant source comprising a dopant, on a surface of a patterned substrate having three-dimensional features or on a material attached to the surface. Forming a layer, and driving a portion of the dopant from the first film layer into the substrate to form a conformal doping profile on the substrate. In some embodiments, forming the first film layer comprises introducing a dopant precursor into the reaction chamber, directly on the surface of the patterned substrate under conditions where the dopant precursor forms an adsorption limiting layer or And adsorbing the dopant precursor on the material to be adhered to the surface, and reacting the adsorbed dopant precursor to form a dopant source.

In some embodiments, forming the first film layer may include atomic layer deposition, and may also include removing the unadsorbed dopant precursor from the reaction chamber. In certain such embodiments, the removal step may occur after the adsorption step but before the reaction step. In some embodiments, the removing step may include pumping the non-adsorbed dopant precursor from the reaction chamber by pumping the reaction chamber to a base pressure using a vacuum pump, while In some embodiments, the removing step may include purging the reaction chamber with an inert gas.

Some methods disclosed herein may further include forming a second conformal film layer containing a dielectric material, and some methods disclosed herein include a dopant comprising a dopant on the material adhered to the surface of the substrate. It may further include forming a third conformal film layer comprising a source, and a substantial portion of the second film layer is intersperse between the first film layer and the third film layer. In certain such embodiments, the methods may further include driving a portion of the dopant from the third film layer into the substrate to form a conformal doping profile on the substrate. In some embodiments, forming the third film layer includes introducing a dopant precursor into the reaction chamber, on the material adhered to the surface under conditions where the dopant precursor forms an adsorption-limited layer. It may include the step of adsorbing the dopant precursor, and reacting the adsorbed dopant precursor to form a dopant source. In some embodiments, adsorbing the dopant precursor when forming the first film layer may include atomic layer deposition, and adsorbing the dopant precursor when forming the third film layer includes atomic layer deposition. You may. In some embodiments, forming the first film layer may include removing the non-adsorbed dopant precursor from the reaction chamber, and forming the third film layer may include non-adsorbed dopant from the reaction chamber. It may also include the step of removing the precursor. In some embodiments, during each formation of the first and third membrane layers, the removal step occurs after the adsorption step but before the reaction step. In some embodiments, the removal may include pumping the unadsorbed dopant precursor from the reaction chamber by pumping the reaction chamber to a base pressure using a vacuum pump. In some embodiments, the removal may include purging the reaction chamber with an inert gas.

In some embodiments, reacting the adsorbed dopant precursor to form the first film layer may include activation using plasma, and reacting the adsorbed dopant precursor to form the third film layer is It may also include activation using plasma. In some embodiments, the plasma is an oxidative plasma. In some embodiments, the plasma is an inert plasma. In some embodiments, driving a portion of the dopant from the first film layer and the third film layer may include a heat mediated diffusion process. In some embodiments, the thermally mediated diffusion process involves annealing. In some embodiments, annealing is laser spike annealing.

In some embodiments, the dopant may include a valence III or V element. In some embodiments, the element is boron, phosphorus, germanium or arsenic. In some embodiments, the dopant is boron, the dopant precursor is an alkyl borate, and the dopant source is boron oxide or boron oxyhydride. In some embodiments, the alkyl borate is trimethyl borate. In some embodiments, the boron oxide is B ₂ O ₃ . In some embodiments, the dopant is arsenic, and the dopant precursor is selected from alkylarsine, alkoxyarsine, and aminoarsine chemical families, and the dopant source is arseno silicate, arsenic doped silicate glass, arsenic oxide Or arsenic oxyhydride. In some embodiments, the dopant precursor is arsine, triethylarsenate, trimethylarsine, triethylarsine, triphenylarsine, triphenylarsine oxide, ethylenebis(diphenylarsine), tris(dimethyl Amino) arsine, or an arsenic-containing compound having the formula As(OR) ₃ (where R is -CH ₃ or -C ₂ H ₅ ). In some embodiments, the dopant source is As ₂ O ₃ and/or As ₂ O ₅ . In some embodiments, the dielectric material of the second film layer is SiO ₂ .

Some methods disclosed herein may further include forming a fourth conformal film layer containing a dielectric material, and some methods disclosed herein include a dopant comprising a dopant on a material adhered to the surface of the substrate. It may further include forming a fifth conformal film layer comprising a source, and a significant portion of the fourth film layer is interposed between the third and fifth film layers. In certain such embodiments, the methods may further include driving a portion of the dopant from the fifth film layer into the substrate to form a conformal doping profile on the substrate. In some such embodiments, forming the fifth film layer includes introducing a dopant precursor into the reaction chamber, depositing the dopant precursor on a material that adheres to the surface under conditions where the dopant precursor forms an adsorption limiting layer. It may include adsorbing, and reacting the adsorbed dopant precursor to form a dopant source. Some methods disclosed herein may further include forming a sixth film layer that is a capping layer, the capping layer being the outermost film layer of the first to sixth film layers relative to the substrate. In certain such embodiments, the capping layer comprises SiO ₂ .

In some of the methods disclosed herein, the step of forming the second film layer is performed under the conditions of introducing a reactant into the reaction chamber, introducing a dielectric precursor into the reaction chamber, and the dielectric precursor forming an adsorption limiting layer. It may also include adsorbing the dielectric precursor onto the material adhered to the substrate, and reacting the adsorbed dielectric precursor with the reactant to form the dielectric material. In some of the methods disclosed herein, the step of forming the fourth film layer includes introducing the reactants into the reaction chamber, introducing the dielectric precursor into the reaction chamber, and the conditions under which the dielectric precursor forms the adsorption limiting layer. It may also include adsorbing the dielectric precursor onto the material adhered to the substrate, and reacting the adsorbed dielectric precursor with the reactant to form the dielectric material. In some such embodiments, the reactant may be an oxidizing agent, such as elemental oxygen, nitrous oxide, water, alkyl alcohol, carbon monoxide or carbon dioxide. In some embodiments, reacting the reactant with the adsorbed dielectric precursor to form a dielectric material may include activation using plasma. In some embodiments, the dielectric precursor is an alkylamino silane (SiH _x (NR ₂ ) _4-x ), wherein x = 1 to 3, and R includes an alkyl group, and halosilane (SiH _x Y _{4 -x} ), (wherein x = 1 to 3, and Y includes Cl, Br, and I). In some embodiments, the dielectric precursor may be BTBAS.

In some embodiments, each of the first to fifth film layers is a monolayer. In some embodiments, the average thickness of each of the first to fifth film layers is between 0.1 and 2 Angstroms. In some embodiments, at least one of the three-dimensional features has a width of about 40 nanometers or less. In some embodiments, the average concentration of dopant on the first to fifth film layers is between about 0.01 and 10% by weight.

A method of doping a patterned substrate in a reaction chamber, which directly forms an alloy comprising a dielectric and a dopant source, on a surface of a patterned substrate having three-dimensional features, or on a material attached to the surface As a step, the dopant source includes a dopant, forming the alloy, and driving a portion of the dopant from the alloy into the substrate to form a conformal doping profile on the substrate. Also disclosed herein. In some such embodiments, forming the alloy may include introducing a dopant precursor and a dielectric precursor into the reaction chamber, adhering to or on the substrate under conditions where the dopant precursor and dielectric precursor form an adsorption limiting layer. Co-adsorption of the dopant precursor and the dielectric precursor on the material, and reacting the adsorbed dopant precursor and the adsorbed dielectric precursor to form a dopant source and an alloy having the dopant source. In some embodiments, forming the alloy may include introducing a third reactant into the reaction chamber and reacting the third reactant with the adsorbed dielectric precursor. In some embodiments, the third reactant may be an oxidant. In some embodiments, reacting the third reactant with the adsorbed dielectric precursor may further include activation using plasma.

Also disclosed are devices for doping a substrate. In some embodiments, the apparatus includes a reaction chamber, a substrate holder in the reaction chamber, one or more dopant precursor gas inlets connected to the reaction chamber, one or more vacuum pumps, and the reaction chamber to the one or more vacuum pumps. It may also include a controller that includes one or more gas outlets to connect, and machine readable code. In some such embodiments, the code may be used to determine the presence of the substrate on the substrate holder, the dopant precursor into the reaction chamber such that the dopant precursor is adsorbed onto the substrate or on a material adhered to the substrate. Instructions for operating one or more dopant precursor gas inlets to introduce, instructions for operating one or more gas outlets to evacuate a non-adsorbed dopant precursor from the reaction chamber, and a membrane layer containing a dopant source It may also include instructions for reacting the adsorbed dopant precursor to form a. In some embodiments, the devices disclosed herein may further include an RF generator configured to excite the plasma within the reaction chamber. In certain such embodiments, instructions for reacting the adsorbed dopant precursor may include instructions for operating the RF generator to excite the plasma that causes the adsorbed dopant precursor to react. In some embodiments, machine readable code comprising a controller may further include instructions for driving a portion of the dopant source from the film into the substrate. In some embodiments, the devices disclosed herein may further include a heater configured to heat the film containing the dopant source. In certain such embodiments, instructions for driving a portion of the dopant into the substrate may include instructions for operating the heater to heat the film to cause thermally mediated diffusion of the dopant from the film into the substrate. It might be.

1 is a schematic illustration of a sequence of operations that may be used to form one or more dopant sources containing conformal film layers through an ALD process.
2 is a schematic illustration of a sequence of operations that may be used to form one or more dielectric conformal film layers through a CFD process.
3 is a schematic illustration of a conformal film stack with intervening ALD B ₂ O ₃ dopant layers and CFD oxide layers, all deposited on the surface of the underlying semiconductor substrate, and also with a capping layer.
4(a) is a schematic illustration of an exemplary A+B stack, with part “B” of the stack serving as a capping layer.
4(b) is a schematic illustration of a conformal film stack with alternating nanolaminate intervening ALD dopant layers and CFD dielectric layers, and also with a capping layer.
4( c) is a schematic illustration of a conformal film stack with alternating monolayers interposed ALD dopant layers and CFD dielectric layers, and also with a capping layer.
4(d) is a schematic illustration of a conformal film stack with alloy layers of dopant source and dielectric, and also with a capping layer.
5 is a graph comparing growth rates on native oxide and conventional B ₂ O ₃ monolayers versus growth rates on CFD oxide for 50 cycles of film formation.
6 is a schematic illustration of a sequence of operations that may be used to deposit a stack of conformal films and to dope a lower semiconductor substrate.
7 is a graph comparing in-wafer (WiW) thickness non-uniformity (NU) between several B ₂ O ₃ stacks deposited using several different methods.
8 are results of 13 point Fourier transform infrared spectroscopy (FTIR) measurements of B ₂ O ₃ films formed using ALD versus CFD, taken at the center and edge of the wafer.
9 shows plots of boron concentration versus substrate depth measured at the substrate center and edge after doping with a conformal stack.
10 also shows plots of boron concentration versus substrate depth measured at the substrate center and edge after doping with different conformal stacks.
11(a) is a schematic illustration of a sequence of operations for doping a lower semiconductor substrate using a conformal film having an arsenic silicate glass (ASG) based dopant layer.
11(b) is a schematic plot of the annealing temperature profile.

Solid-state diffusion of p-type and n-type dopants from conformally deposited films is presented herein as an alternative to doping substrates using incumbent ion implantation technology. . Doping through conformally deposited films, for example, when doping 3D structures, such as ultratrash allow junction regions and/or source/drain extension regions of 3D transistors (such as pMOS FinFETs). It may be superior to ion implantation. In general, doping through conformally deposited films is useful for doping many high aspect ratio device structures, and conventional ion implantation or directional doping methods may be appropriately used in many scenarios where they are unsuitable. Such conformal doping may employ the use of deposition techniques such as atomic layer deposition (ALD). In some contexts, the formation of ALD, referred to as conformal film deposition (CFD), is employed. In particular, when a thin layer of n-doped or p-doped conformal film is formed through ALD on vertical surfaces of device structures, conformal doping of these vertical surfaces may be achieved. Such conformal doping has been observed, in some cases, to increase the current density in 3D devices by 10% to 25% due to reduced series resistance. See VLSI 2011 by Yamashita et al. In addition to conventional silicon-based microelectronics, other applications of ALD doping include microelectronics and optoelectronics based on III-V semiconductors such as GaAs, and II-VI semiconductors such as HgCdTe, and photovoltaic cells, flat panel displays and electrochromic technology. It includes.

Doping through conformally deposited films involves the formation of one or more dopant source conformal film layers containing a dopant source—eg, on lateral and vertical surfaces of a high aspect ratio device structure. In some embodiments, dopant source layers may be interposed with silicon oxide conformal film layers, which layers are formed by growing them over each other, in turn, alternately, sequentially. If a sufficient number of dopant source layers are present, the dopant may be transferred into the substrate by driving a portion of the dopant from the dopant source conformal film layers into the substrate, such as the underlying silicon substrate. The dopant driven into the substrate and the dopant source in the conformal film layer(s) may be just the same, or the dopant driven into the substrate may be a species chemically related to the dopant source, such as, for example Note that the dopant source may be a phosphorus containing compound, or the dopant itself may be a phosphorus atom in the phosphorus containing compound.

In some embodiments, it may be possible to use a chemical vapor deposition (CVD) process to deposit dopant source layers. In some embodiments, dopant source layers formed through CVD may be interposed with conformal silicon oxide layers. However, thermally grown CVD formed dopant source layers by flowing B ₂ H ₆ (or PH ₃ or AsH ₃ (arsine) for n-type doping) may, in some cases, be deposited as ( It has been found that, in terms of both incorporation of the dopant into the as-deposited dopant source film layer and transfer of the dopant into the underlying substrate, it may exhibit less than optimal wafer uniformity. Also, an array of 3D structures on the same die with different geometric constraints may exhibit pattern loading. That is, features with different geometrical features (eg, different aspect ratios) may have different doping profiles when CVD-based dopant source layers are used.

In some embodiments, atomic layer deposition (ALD) may be used to deposit a dopant source containing conformal film layers. In some embodiments, these layers may be interposed with conformal oxide layers. In some embodiments, oxide or oxyhydride film layers deposited through ALD may be used as conformal film layers containing a dopant source. In certain such embodiments, the dopant precursor used to form these layers may be an organometallic precursor. In certain such embodiments, trimethyl borate (TMB) may be used as an ALD dopant precursor in the process of forming boron containing conformal film layers interposed with oxide layers to form an oxide stack. In other embodiments, arsenic (As) doped silicate glass (ASG) or arsenic oxide (e.g. As ₂ O ₃ , As ₂ O ₅ ), or phosphorus (P) doped silicate glass (PSG) or phosphorus oxide ( For example, P ₂ O ₅ ) may serve as a dopant source in the conformal film layer formed through ALD. As described below, plasma activation can be used after adsorption of the dopant precursor to produce conformal films containing B ₂ O ₃ , or P ₂ O ₅ or PSG or ASG, or As ₂ O ₃ , or As ₂ O ₅ It might be. Depending on the embodiment, certain stack engineering concepts may be used to control boron, phosphorus, or arsenic concentrations in these films. Of course, other dopant precursors may also be employed in ALD processes to produce dopant source conformal film layers, and depending on the dopant precursor, a conformal film containing gallium, phosphorus and their respective oxides and oxyhydrides, etc. Layers may be made.

A conformal film layer containing a dopant source is referred to as a “source” layer because it provides a source of dopant species (eg, dopant atoms such as boron, phosphorus, gallium and/or arsenic). The dopant source layer serves as a source of dopant for doping the bottom (or top) structure in the device. After the dopant source layer is formed (or during its formation), the dopant species are driven into or otherwise incorporated into adjacent structures in the device being manufactured. In some embodiments, the dopant species are driven by an annealing operation during or after forming the dopant source conformal film layer. As discussed above, the substantial conformal nature of the dopant source layers deposited using ALD allows effective doping of non-conventional device structures, including structures that require doping in 3D, for example. In some embodiments, the dielectric layer serves as a base source layer into which the dopant layer is incorporated. For example, doped silicon oxide may be used as a diffusion species for boron, phosphorus, arsenic, gallium, and the like. In some embodiments, boron doped silicate glass (BSG), phosphorus doped silicate glass (PSG), boron-phosphorus doped silicate glass (PSG), or arsenic doped silicate glass (ASG) may be used.

Conformal films formed using ALD and comprising a dopant source for diffusion into the underlying substrate may have several benefits and advantages. First, in some embodiments, often highly conformal films may be formed by ALD processes at fairly low temperatures. A high degree of conformality for these films is beneficial, because removal may be overetched (or underetched//) to the extent that the film layers used to dope the underlying layer may be sacrificial and these films are non-conformal. Undercut), which poses a significant challenge. ALD processes may also provide conformal films with extremely well controlled doping concentrations. In some embodiments, this is achieved by using ALD to intervene the doped layers with undoped oxide layers and by changing the ratio of the doped layer to the doped layer to precisely control the overall stack concentration of the dopant source species. It may be. That is, the doping level can be strictly controlled by the frequency with which the doping layer is deposited into non-doped layers and also by controlling the conditions of the doping cycle that affect the concentration of the dopant in the dopant source containing layers. For example, in some embodiments, a dopant source with significant steric hindrance may provide a mechanism for controlling the properties of the deposited doped layers.

In addition, conformal films deposited through ALD may have other applications besides being used as a dopant source for the underlying substrate. Other applications for conformal oxide films deposited through ALD include interlayer dielectric (ILD) applications, intermetal dielectric (IMD) applications, pre-metal dielectric (PMD) applications, dielectric liner for through-silicon via (TSV) Applications, including resistive RAM (ReRAM) applications and/or stacked capacitor manufacturing applications in DRAM.

Other uses for ALD glasses include, but are not limited to, passivation, reflow, hermetic sealing, capacitor dielectrics, and the like.

Also, in some embodiments, doped films are used as etchable layers, such as high-etching-rate sacrificial oxides used in various stages in integrated circuit IC manufacturing, such as during patterning stages of integrated circuit (IC) manufacturing. You can also find applications. In certain such embodiments, the etchable layer for use in IC fabrication may be a glass layer with a tunable wet etch rate, where the etch rate is tunable by doping level. That is, the doping level is selected to provide a predefined etch rate. These doped films may be conformal films formed through ALD. In certain embodiments, the etchable layer is a silicate glass layer comprising a dopant such as arsenic, phosphorus, boron, germanium, or combinations thereof. In particular, boron-containing silicate glass (BSG) deposited through ALD has a much higher etch rate than undoped CFD oxide or thermal oxide, and the etch rate of BSG appears to be tunable to boron concentration. Thus, doped conformal films deposited through ALD may simply be used as conformal sacrificial layers or spacers in front-end-of-line (FEOL) structures. Faster etch rates and selectivity in the underlying layer are key features in selecting etch rate selective ALD conformal films.

Formation of conformal film layers containing dopant source through ALD

The concept of the ALD "cycle" is important with respect to various parts of the description that follows, and in particular to the discussion of the deposition of multiple conformal film layers through multiple "cycles" of ALD. In general, the basic set of steps that result in the deposition of at least a partial conformal film layer on the substrate surface may be referred to as a single ALD “cycle”. Typically, the ALD cycle will include only the steps necessary to transfer each reactant to the substrate surface to adsorb and then react these adsorbed reactants to form a partial layer of the film. Of course, the cycle may include certain minor steps of sweeping one of the reactants or byproducts out of the reaction chamber and/or subjecting the deposited conformal membrane layer (or partial membrane layer) to treatment. Generally, a cycle represents a single iteration of a unique set of operations resulting in the deposition of an entire or partial conformal film layer.

1 shows a schematic diagram illustrating a general sequence of operations from left to right over time along a horizontal axis that may be used to form one or more dopant source containing conformal film layers through an ALD process. This schematic diagram simply illustrates the baseline sequence of steps, with the addition of ALD forming conformal film layers as well as other ancillary actions depending on the embodiment and the nature of the dopant source and corresponding dopant precursor species in addition to the illustrated actions Note that, substitution, and/or intervening.

Referring to Figure 1, in operation (i), a suitable dopant precursor is introduced into the reaction chamber under conditions that may cause the dopant precursor to form an adsorption limiting layer (given a sufficient amount of time duration and a sufficient amount of precursor). And is adsorbed on the substrate surface (or on a material attached to the substrate). The duration of operation (i) is selected to allow the precursor to adsorb on the substrate surface in an amount sufficient to support one cycle of ALD film growth. In some embodiments, the precursor saturates the substrate surface forming the adsorption limiting layer described above. In other embodiments, a layer is formed by only partially saturating the substrate surface with the precursor (eg, due to insufficient time or total amount of saturation for the precursor). In certain embodiments, a dopant precursor is provided to the reaction chamber by flowing a dopant precursor gas with a carrier gas. An inert gas such as argon may serve this purpose. Following adsorption of the dopant precursor, in operation (ii), the remaining non-adsorbed dopant precursor still present in the reaction chamber, for example, pumps the reaction chamber down to the base pressure (referred to as "pump to base") and And/or optionally, purging the reaction chamber with an inert gas (referred to as "inert purge") to flush out any remaining non-adsorbed dopant precursors. Thereafter, the reaction of the adsorbed dopant precursor occurs in operation (iii), where the reaction proceeds through plasma activation, using inert plasma activation and/or oxidative plasma activation to form a layer of the dopant source containing conformal film. . Finally, in operation (iv), a pump and/or inert purge to another base is performed to remove any reaction byproducts. Operations (i)-(iv) may be referred to collectively as referred to above, referred to as ALD cycles and provide a single cycle of dopant ALD film deposition. 1 also schematically illustrates that this ALD cycle may be repeated one or more times to form multiple dopant source-containing conformal film layers (see operation (v)). Thus, in some embodiments, operations (i) to (iv) are consistently repeated at least once, or at least twice, or at least 3 times, or at least 5 times, or at least 7 times, or at least 10 times in succession. do. Dopant ALD membranes may be between 0.1 Å and 2.5 당 per ALD cycle, or between 0.2 Å and 2.0 당 per ALD cycle, or between 0.3 Å and 1.8 당 per ALD cycle, or 0.5 당 per ALD cycle. Between 1.5 Å or less, or between 0.1 Å and 1.5 당 per ALD cycle, or between 0.2 Å and 1.0 당 per ALD cycle, or between, or between 0.3 Å and 1.0 당 per ALD cycle, or It may be deposited at a rate of between 0.5 µs and 1.0 µs per ALD cycle or at a rate of that degree.

Several dopant precursors may be used with the sequence of previous operations to form the dopant source containing conformal film layers. In some embodiments, a suitable dopant source may be elemental arsenic or arsenic doped silicate glass (ASG), or arsenic compounds such as As ₂ O ₃ and/or As ₂ O ₅ . In other embodiments, a suitable dopant source may be elemental boron or a boron compound such as B ₂ O _3, and a suitable dopant precursor may be a boron compound such as an alkyl borate. For example, trimethyl borate (TMB) (shown below) is an alkyl borate that acts particularly well as a dopant precursor to form dopant source B ₂ O ₃ , but other dopant precursors also form several boron-based dopant sources. It may be suitable. Further, as described below, dopant sources based on elements other than boron and arsenic may also be suitable, such as, for example, dopant sources based on gallium or phosphorus.

As indicated above, plasma activation in operation (iii) may involve exposure of adsorbed dopant precursors to either an oxidative plasma or an inert plasma. The oxidative plasma may be formed from one or more oxidizing agents such as O ₂ , N ₂ O, or CO _2, and may optionally include one or more diluents such as Ar, N ₂ , or He. In one embodiment, the oxidative plasma is formed from O ₂ and Ar. A suitable inert plasma may be formed from one or more inert gases such as He or Ar. Note that inert plasma activation may require a longer duration of RF radiation-longer than 10 seconds in some embodiments-to generate a plasma that forms sufficient reactivity in the adsorbed dopant precursor. Without being limited to a particular theory, longer purge durations may be attributed to longer life spans associated with He (or other inactive) metastable species.

Further, in some embodiments, pumping to the base refers to pumping the reaction chamber to base pressure by directly exposing the reaction chamber to one or more vacuum pumps. In some embodiments, the base pressure may typically be only a few milliTorr (eg, between about 1-20 mTorr). Further, as described above, the pumping step to the base may or may not be performed by an inert purge, so the carrier gas may flow when one or more valves open the conduction path to the vacuum pump, or It may not.

Atomic layer deposition to form a conformal film layer containing a dopant source may be performed at various temperatures. In some embodiments, a suitable temperature in the reaction chamber is between 25 °C and 450 °C or higher, or between 50 °C and 300 °C or higher, or between 20 °C and 400 °C or higher, or between 200 °C and 400 °C It may be in the range of or between, or between 100 °C and 350 °C or so. However, unlike thermal CVD processes involving, for example, B ₂ H ₆ , the introduction of only TMB (or other dopant precursors) does not form a layer of B ₂ O ₃ -instead following the surface adsorption of the dopant precursors Note that the plasma activation step (as described) follows. Atomic layer deposition to form conformal film layers containing a dopant source may be performed at various chamber pressures. In some embodiments, a suitable pressure in the reaction chamber is between 10 mTorr and 10 Torr or so, or between 20 mTorr and 8 Torr or so, or between 50 mTorr and 5 Torr or so, or 100 mTorr and 2 Torr It may be in the range of or between. Several RF power levels may be employed to generate the plasma used in operation (iii). In some embodiments, suitable RF power is between 100 W and 10 kW or so, or between 200 W and 6 kW or so, or between 500 W and 3 kW or so, or between 1 kW and 2 kW, or It may be in that range. Several dopant precursor flow rates may be employed in operation (i). In some embodiments, a suitable flow rate is between 0.1 mL/min and 10 mL/min or so, or between 0.5 mL/min and 5 mL/min or so, or between 1 mL/min and 3 mL/min, or It may be in that range. Different gas flow rates may be used in different operations. In some embodiments, the general gas flow rate may range between 1 L/min and 20 L/min or so, or between 2 L/min and 10 L/min or so. In the optional inert purge steps in operation (ii) and operation (iv), the burst flow rate employed is between 20 L/min and 100 L/min or so, or 40 L/min and 60 L/ It may be in the range of min or so.

When using TMB as a dopant precursor with O ₂ /Ar plasma activation, it may not be appropriate to have co-flowed O ₂ and TMB in the reaction chamber due to the stability aspect (or other possible aspect). In these embodiments, the pump and/or inert purge step to the base follows the step of introducing and adsorbing the dopant precursor, and thus, the non-adsorbed dopant precursor before starting the flow of O ₂ into the reaction chamber. You can also remove If O ₂ is already flowing (perhaps from the previous ALD cycle), the flow may be stopped prior to the introduction of TMB into the reaction chamber. In some embodiments, it may be appropriate to use a separate line charge step to establish the flow of O ₂ into the chamber after post-dose purge. The pump (and selective inert purge) step to the base to remove non-adsorbed TMB prior to the introduction of O ₂ has been found to prevent gas phase CVD reactions. All other process parameters remain the same without a pump (and optional inert purge) step to the base, and the uniformity of the 100X conformal film (100 layers) formed from 100 ALD cycles degrades from 0.3% to 4%. I figured it out.

The adsorption step of the reaction sequences described above (and other similar related reaction sequences) may result in the entire dopant forming a adsorption limiting layer (given a sufficient duration of time and a sufficient amount of precursor)-i.e., a single Conformal film growth in the ALD cycle occurs under conditions limited to the amount of dopant precursor that may be adsorbed on the substrate surface at one time. The self-limiting nature of these reactions results in a deposited film that exhibits an excellent degree of conformity and uniformity to the density of the dopant source contained in the film.

As described above, trimethyl borate is one suitable dopant precursor, but depending on the embodiment, other compounds may also serve as suitable dopant precursors. For example, other suitable boron-based dopant precursors include other alkyl borates such as triethyl borate, triisopropyl borate and tri-n-butyl borate, and trimethylboron, triethylboron, triphenylboron, tri-i-propyl borate. , Tri-n-amyl borate, B-tribromoborazine, tris(pentafluorophenyl)borane, and other similar boron-containing compounds. Additionally, dopant sources based on elements other than boron may also be suitable. Examples include dopant sources based on other elements suitable for doping a semiconductor substrate, such as gallium, phosphorus, arsenic, or other valence III and V elements. Arsenic-silicate or arsenic-doped silicate glass (ASG), arsenic oxides (e.g., As ₂ O ₃ , As ₂ O ₅ ) are specific dopant sources based on arsenic, which may include conformal films deposited through the ALD process. ) And arsenic oxyhydride. Arsenic-based dopant precursors may include, but are not limited to, alkylarsine, alkoxyarsine, and aminoarsine chemical groups, and include the following specific compounds: arsine, triethylarsenate, trimethylarsine, Triethylarsine, triphenylarsine, triphenylarsine oxide, ethylenebis(diphenylarsine), tris(dimethylamino)arsine, and As(OR) ₃ [where R is -CH ₃ or -C ₂ H ₅ or other alkyl groups (including saturated or unsaturated alkyl groups)] and other similar arsenic-containing compounds. Certain dopant sources based on phosphorus, which may include conformal films deposited through the ALD process, may include, but are not limited to, phosphorus doped silicate glass (PSG). Dopant precursors based on phosphorus may include, but are not limited to, triethoxyphosphine oxide, trimethylphosphate, trimethylphosphite, and other similar phosphorus containing compounds. The choice of dopant precursor is typically governed by ease of integration into existing delivery systems, purity requirements, and overall cost.

However, in many cases, arsenic appears to have distinct advantages over phosphorus for the purpose of forming conformal film layers to dope the underlying substrate. For example, arsenic has a much shorter diffusion length in silicon lattice than phosphorus, and thus has the potential to dope ultrashell junctions smaller than 20 nm. Second, the solid solubility of arsenic in silicon is higher than that of phosphorus, indicating that higher concentrations of arsenic dopants can be realized at much narrower junctions. Both of these properties are useful in situations that mitigate short channel effects in scaled devices. However, arsenic spin-on-glass (As-SOG) (see Journal of the Korean Physical Society, Vol. 51 (December 2007), pp. S265-S269) is a very few method pursued by researchers on ASG. It seems to be one of them, and achieving perfect conformity and thickness control by this technology has been and will continue to be a challenge. Thus, forming conformal film layers of arsenic based dopant sources, such as arsenic oxide or oxyhydride, using various ALD based methods disclosed herein is a useful and desirable technique for doping certain types of device structures.

Dielectric conformal film layer via CFD process (e.g. SiO/SiO ₂ Layer)

Some methods disclosed herein for depositing conformal films (and using conformal films for doping the underlying semiconductor substrate) do not contain a dopant source but instead consist of conformal film layers composed of other components. This involves depositing intervening multiple dopant source containing conformal film layers. For example, a dielectric conformal film layer containing SiO/SiO ₂ is interposed in the form of a film dielectric layer in dopant source-containing conformal film layers as part of a “stack” of the conformal film, as will be described in detail below. It may also be deposited through a conformal film deposition (CFD) process (as schematically shown in FIG. 2). In some embodiments, an ALD dopant layer is deposited at the interface or surface of the underlying semiconductor substrate, followed by CFD dielectric layers with dopant ALD layers every X ALD cycles, undoped protection that may be a CFD silicon oxide film It is selectively topping with a "capping" layer. This “stack” configuration is schematically illustrated in FIG. 3 as B ₂ O ₃ serves as a dopant source and oxide layers intervening as dielectric layers.

Thus, the concept of the dielectric CFD "cycle" is important in various parts of the description that follows, and in particular in relation to the discussions regarding the deposition of multiple conformal film layers through multiple dopant ALD "cycles". As in the dopant ALD cycle discussed above, the baseline set of operations that result in the deposition of at least a partial conformal film dielectric layer may be referred to as a single dielectric CFD “cycle”. Typically, the dielectric CFD cycle will include only the steps necessary to deliver and adsorb each reactant to the substrate surface and then react these adsorbed reactants to form a partial layer of dielectric film. Of course, as in the dopant ALD cycle discussed above, the cycle is such as sweeping one of the reactants or by-products out of the reaction chamber and/or subjecting the deposited conformal membrane layer (or partial membrane layer) to treatment. It may also include certain ancillary steps.

2 shows a schematic diagram showing a general sequence of operations from left to right over time along the horizontal axis, which may be used to form one or more dielectric conformal film layers through a CFD process. Note that this schematic diagram simply shows a baseline sequence of steps, and depending on the nature of the embodiments and the dielectric film, other ancillary operations may be added, substituted, and/or intervened in the embodiments described herein. Initially in sequence, during operation A, a vapor phase oxidant is introduced into a reaction chamber containing a semiconductor substrate on which CFD films are to be deposited. Examples of suitable oxidizing agents include elemental oxygen (eg, O ₂ or O ₃ ), nitrous oxide (N ₂ O), water, alkyl alcohols such as isopropanol, carbon monoxide, and carbon dioxide. Oxidizing agents are often provided with inert gases such as argon or nitrogen.

Next, in operation B, a dielectric precursor is introduced into the reaction chamber. The duration of operation B is selected to allow the precursor to adsorb on the substrate surface in an amount sufficient to support one cycle of film growth. In some embodiments, the precursor saturates the substrate surface. The dielectric precursor is selected from its ability to produce a dielectric of the desired composition. Examples of dielectric compositions include silicon oxide (including silicate glass), silicon nitride, silicon oxynitride and silicon oxycarbide. Examples of suitable dielectric precursors include several alkylamino silanes (SiH _x (NR ₂ ) _4-x ) and x = 1 to 3, and R contains alkyl groups such as methyl, ethyl, propyl, and butyl in several isomer configurations. do. Examples of suitable dielectric precursors also include several halosilanes (SiH _x Y _4-x ), where x = 1 to 3 and Y includes Cl, Br, and I. More specific examples of suitable dielectric precursors include several bis-alkylamino silanes and steric hindered alkyl silanes. In some embodiments, bis(tert-butylamino)silane (BTBAS) is a suitable dielectric precursor for producing silane oxide.

The oxidant that was introduced into the chamber during operation A may continue to flow during operation B. In certain embodiments, the oxidant continues to flow at the same concentration and same rate as during operation A. Upon completion of operation B, the flow of the dielectric precursor into the chamber is terminated and operation C begins as shown. During operation C, the oxidizing agent (and inert gas, if present) may continue to flow as during operations A and B, purging potentially remaining non-adsorbed dielectric precursors from the reaction chamber. In other embodiments, the flow of oxidant may be shut off and purge may be performed with only an inert gas. In some embodiments (not shown in FIG. 2 ), removal of the non-adsorbed dielectric precursor from the reaction chamber may be accomplished through a pump operation to a base similar to the operation described above.

After removing the non-adsorbed dielectric precursor during operation C, in operation D, the precursor reacts on the substrate surface to form part of the dielectric film. In various embodiments, operation D may involve applying plasma to the adsorbed dielectric precursor to drive the reaction. In some embodiments, the reaction is an oxidation reaction. Some of the oxidizing agent flowing into the reaction chamber may be adsorbed on the substrate surface along with the dielectric precursor, thus providing an oxidant readily available for plasma mediated surface reaction. In some embodiments, the flow of oxidant to the reaction chamber may continue through the duration of operation D as (optionally) shown in FIG. 2, and this flowing oxidant is used to drive oxidation of the adsorbed dielectric precursor. An oxidative plasma may be formed.

Operations A through D collectively provide a single cycle of dielectric CFD film deposition. However, it should be understood that other CFD processes may be used instead of the basic cycle described herein. In the described embodiment, the CFD cycle (consisting of operations A to D) is performed without introduction of any dopant species or dopant precursors (of course dopants can be introduced). In various embodiments, the dielectric CFD cycles represented by acts A-D are repeated one or more times consecutively prior to the introduction of any dopant species or dopant precursor. This is schematically indicated by operation E in FIG. 2. Thus, in some embodiments, operations A-D are repeated at least once or at least 2 or at least 3, or at least 5, or at least 7 or at least 10 before initiating the dopant ALD cycle as described above. . The CFD dielectric film may be between 0.1 Å and 1.5 당 per CFD cycle, or about 0.2 Å and 1.0 CF per CFD cycle, or between 0.3 Å and 1.0 당 per CFD cycle, or 0.5 per CFD cycle. It may be formed at a rate between Å and 1.0 Å or at a rate of about that. Over each of the one or more CFD cycles, the oxidant may continue to flow into the reaction chamber as schematically illustrated in FIG. 2.

In certain embodiments, plasma activation involves RF power at any frequency suitable for causing the reaction of the adsorbed dielectric precursor in operation D. In some embodiments, the RF power may include independently controlled high frequency RF power and low frequency RF power generated by an RF power source that may be operated independently of each other. Suitable low frequency RF powers may include, but are not limited to, a frequency range between about 200 kHz and 1000 kHz. Suitable high frequency RF powers may include, but are not limited to, frequencies between about 10 MHz and 80 MHz, for example 13.56 MHz. As such, RF power supplies and matching networks may be operated in any suitable power range to form plasma within the reaction chamber. Examples of suitable plasma generated RF power include RF power between about 100 W and 3000 W for high frequency plasma (based on a per wafer basis), and RF power in the range between about 100 W and 10,000 W for low frequency plasma. It may, but is not limited to these. One or more RF power supplies may be operated at any suitable duty cycle. Examples of any suitable duty cycle include, but are not limited to, duty cycles between about 5% and 90%. These RF powers and frequencies may also be suitable for use in the plasma activated operation of the dopant ALD cycle described above.

Reaction chamber pressures suitable for performing operations A to D generally include, but are not limited to, pressures between 0.5 Torr and 5 Torr or higher, preferably between 2 Torr and 4 Torr or higher. . It has been found that pressures of up to about 10 Torr (or up to about 9 Torr) work well for certain plasma pretreatments (of the lower substrate) prior to exposure to the dopant.

Stack engineering: capping layer

In some embodiments, the dopant source-containing conformal film may be hygroscopic with the ability to adsorb sufficient ambient humidity to affect the observed physical properties and functions. For example, conformal membranes containing B ₂ O ₃ , As ₂ O ₃ , As ₂ O ₅ , P ₂ O ₅ , PSG, or ASG deposited through ALD may be hygroscopic and have ambient moisture such as volatile boric acid. When exposed to, hydroxide may be formed. Volatilization of boric acid changes the ability of these films to dope the underlying substrate. Therefore, it is often advantageous to protect the conformal film layers containing the dopant source from exposure to moisture.

Thus, the prevention or minimization of moisture exposure is deposited on top of the bottom dopant source layer or stack of layers, essentially acting as a physical barrier between these layers with any ambient moisture present in the reaction chamber, as illustrated in FIG. 3. Can also be achieved by employing a capping layer. Figure 4(a) shows an exemplary A+B stack and part "B" of the stack serves as a capping layer. In some embodiments, the capping layer may include one or more oxides, such as SiO and SiO ₂ , formed from dielectric precursors deposited and reacted in a CFD process as described above. In some embodiments, the dielectric precursor may be bis(tert-butylamino)silane (BTBAS). In other embodiments, the capping layer may include one or more nitride or oxynitride species. In some situations, it has been found that, without the capping layer, it is not possible to detect the presence of B ₂ O ₃ by thickness metrology.

In some embodiments, the capping layer is engineered by controlling the capping layer chemistry during the deposition process to adjust the diffusion characteristics of the dopant towards the underlying semiconductor substrate. Without being limited to a particular theory, by depositing a suitable capping layer, despreading of the dopant source (i.e., diffusion of the dopant away from the membrane-substrate interface) may be blocked by the capping layer thereby preventing infinite storage of the dopant in the stack It is assumed that it can be effectively simulated.

Stack engineering: deposition of multiple dopant source film layers through multiple ALD cycles interposed with other film layers, such as a dielectric CFD layer

It is possible to deposit multiple dopant source-containing conformal film layers sequentially through ALD processes, and in some embodiments and in some types of dopant precursors, this may be the preferred approach. It has been found, however, that in some cases, depositing dopant film layers sequentially using sequential ALD cycles tends to be somewhat self-inhibiting. In particular, it has been found that in TMB acting as a dopant precursor, self-inhibition limits the TMB nucleation on the B ₂ O ₃ monolayer to less than 0.2 μA per ALD cycle. In addition, this growth rate further decreases after a certain number of dopant layers are deposited. Indeed, in one embodiment, it has been found that the total thickness of the B ₂ O ₃ film using sequential ALD cycles does not change significantly between the 50th ALD cycle and the 100th ALD cycle. Consequently, in some dopant sources and their corresponding dopant precursors, the dopant concentration in the deposited conformal film cannot be increased simply by increasing the dopant source concentration in the film or by increasing the film thickness. For example, referring to Figure 4(a), the total amount of B ₂ O ₃ available cannot be increased simply by increasing the thickness of the “A” layer in the “A+B” stack described above. This is in contrast to boron-containing layers deposited using a CVD process, where the boron concentration is increased by increasing the duration of the CVD process and/or increasing the flow of the dopant precursor to increase the thickness of the deposited boron-containing layer. It can simply be adjusted.

However, in some cases the dopant source-containing film layer may experience faster growth when formed through ALD over some non-dopant-containing film layer, such as, for example, a non-dopant dielectric layer, or more specifically a non-dopant oxide layer. Found out. In addition, when the above-described dielectric layer (e.g., oxide layer) is deposited through a CFD process, the dopant source layer formed through ALD thereon is much better than on the native dielectric layer (e.g., native oxide layer). I found out that it might show faster growth. For example, it has been found that the B ₂ O ₃ dopant source layers formed from TMB precursors deposited through ALD on top of the CFD deposited silicon oxide layer show a growth rate greater than 1 kPa per ALD cycle as shown in FIG. 5. . Without being limited to a particular theory, this may be due to the greater number of available hydroxyl surface sites on which TMB may adhere on a coalesced CFD oxide layer. In some embodiments, a “start” layer of CFD oxide is deposited on the substrate surface prior to depositing the first ALD dopant layer to promote growth of the ALD dopant layer and increase boron concentration closest to the dopant source-substrate interface. It may be formed. FIG. 5 also shows the growth rate for CFD oxide and the native oxide and the existing B ₂ O ₃ monolayer over 50 deposition cycles at a temperature of 400° C. using oxidative plasma (O ₂ ) to activate the adsorbed TMB precursor. Compare the growth rate for. As shown in the figure, the dopant ALD layers grow at a rate of 0.3 kV per ALD cycle (up to 1 kV per ALD cycle on CFD oxide) on top of the native silicon oxide layer but ALD on top of the existing B ₂ O ₃ monolayer It has been found that only 0.21 kPa per cycle grows. Thus, non-CFD (non-CFD) deposited silicon oxide or hydroxyl-terminal containing oxide layers may also promote or increase nucleation rates of ALD dopant layer growth, at least in some cases, but not to the same extent.

Due to this, by nucleating TMB ALD layers on thin films of CFD silicon oxide, the effective boron concentration can be increased for the same overall stack thickness. By varying the spacing and/or frequency of these CFD oxide layers throughout the stack, it is possible to fine tune the boron concentration. 4(b) and 4(c) show different stacking strategies, such as employing nanolaminates and monolayers, respectively. Single layer laminates are made by alternating single cycles of CFD silicon oxide deposition and ALD dopant layer deposition. Nanolaminates are made by alternating two or more cycles of ALD dopant layer deposition and two or more cycles of CFD silicon oxide layer deposition. In some cases, more than two sequential cycles of dopant layer and/or oxide layer deposition may be employed in forming nanolaminates. For example, the repeating sequence of deposition cycles used to construct the nanolaminate is 2:2 (ie, 2 oxide cycles after 2 dopant cycles, this sequence is repeated one or more times), or 2:3, or 2 :5, or 3:2, or 5:2. Thus, by adjusting the deposition sequence and the ratio of dopant cycles to oxide cycles, the dopant concentration (eg, boron concentration) for a given stack thickness (eg, about 100 mm 2 -200 mm 2) may be adjusted and controlled.

Accordingly, FIG. 6 shows a schematic diagram showing a sequence of operations that may be used to deposit a stack of conformal films and to dope a lower semiconductor substrate. Again, the sequence of operations proceeds from left to right over time along the horizontal axis. Again, similarly to FIGS. 1 and 2, this schematic simply represents a baseline sequence of steps, and depending on the embodiment and various considerations, other ancillary actions may be added, substituted, and/or added to the illustrated actions, and/or Also note that it may be intervened. These considerations may include, for example, the nature of the design of the conformal stack, the selection of the dopant source and the corresponding selection of the corresponding dopant precursor species, and also the selected composition of the dielectric layer.

Referring to FIG. 6, in this particular embodiment, one or more dielectric layers are first on the surface of the lower semiconductor substrate, using the dielectric CFD cycle schematically illustrated in FIG. 6 by operations A, B, C, and D. It is deposited directly (or on a material adhered to the substrate). The operations A, B, C, and D in FIG. 6 correspond to the A, B, C, and D operations schematically illustrated in FIG. 2, and the aforementioned discussion regarding those operations also applies here. As in FIG. 2, operations A to D represent one dielectric CFD cycle of film growth, and also as shown in FIG. 2, operation E in FIG. 6, additional dielectric CFD cycles followed by an initial cycle followed by additional conformal dielectric film layers It is schematically shown that they may be formed. As such, the baseline process schematically illustrated in FIG. 6 includes and begins with the baseline dielectric CFD process illustrated in FIG. 2.

Following deposition of one or more dielectric film layers in operations A to E, the reaction chamber is pump-to-base (as described above) in operation F, and optionally (as also described above) Purged with inert gas. Operation F serves to remove any remaining dielectric precursors, oxidizing species, or any other remaining species from preceding dielectric CFD cycles from the reaction chamber. Of course, in some embodiments, the removal operation F may not be necessary because, for example, a significant amount of the remaining species are not present in the reaction chamber after the inclusion of dielectric CFD cycles, or simply the remaining species. This is because it does not adversely affect the dopant ALD cycles that will follow.

After the first set of dielectric film layers are deposited and (if necessary) the reaction chamber is prepared, a first dopant ALD cycle is performed in operations G, H, I, and J. Operations G to J correspond to operations (i) to (iv) of FIG. 1, and the discussion related to operations (i) to (iv) of FIG. 1 also applies here to operations G to J. As described above with respect to operations (i)-(iv), in operation G, under conditions that the dopant precursor may form an adsorption limiting layer, a suitable dopant precursor is introduced into the reaction chamber and on the substrate surface (or Adsorption). After adsorption of the dopant precursor, in operation H, any remaining non-adsorbed dopant precursor still present in the reaction chamber is removed through a pump to the base and optional inert purge. The reaction of the adsorbed dopant precursor then takes place in operation I, where the reaction proceeds through plasma activation using inert plasma activation and/or oxidative plasma activation to form a layer of conformal film containing the dopant source. Finally, in operation J, a pump and/or an inert purge to another base is performed to remove any reaction byproducts. As described above in relation to operations (i) to (iv), operations G to J collectively represent a single dopant ALD cycle providing a single dopant ALD film layer. As schematically indicated by operation K in FIG. 6, the ALD cycle represented by operations G to J may be repeated one or more times to form multiple dopant source containing conformal film layers.

At this point in the baseline conformal stack building process schematically illustrated in FIG. 6, the lower semiconductor substrate has a set of dielectric CFD layers deposited thereon and another set of dielectric CFD layers deposited thereon. Dopant ALD layers. The set of dielectric CFD layers and the set of dopant ALD layers may each have the same number of layers, as described above, or, in some embodiments, a different number of layers. In either case, this set of dopant ALD layers may constitute the extent of dopant sources present in the conformal stack. In other words, in some embodiments, additional dopant ALD layers may not be deposited. However, other embodiments may have multiple sets of dopant ALD layers. Thus, for example, in operation L, the sequence of operations A to K may be repeated one or more times, resulting in one or more additional sets of dielectric CFD layers alternating with one or more additional sets of dopant ALD layers. The actual number of times operations A through K are repeated depends on the desired overall thickness of the conformal film stack, the desired thickness of the dielectric and dopant layer sets, and the amount/concentration of the dopant intended to be included in the stack. Also, if the schematic process of FIG. 6 is strictly followed, the second set of dielectric CFD layers will have the same number of layers as the first set of dielectric CFD layers, and similarly the second set of dopant ALD layers will Note that it will have the same number of layers as one set of dopant ALD layers. However, it will be understood that the number of layers in each set of successive dielectric CFD and dopant ALD layers may vary, and in some embodiments, changing the number of layers in this manner may be a desirable approach.

After deposition of the dielectric and dopant conformal film layers is completed, an optional capping layer may be applied in operation M of FIG. 6. Potential capping layers are described above. As shown in Figure 6, in some embodiments, the capping layer may be formed by repeating the dielectric CFD cycle of operations A to D one or more times. Note, however, that the capping layer need not necessarily be formed by employing operations A to D. In some embodiments, the capping layer can be formed by employing a CFD oxide chemical that is completely different from that employed in operations A to D; For example, precursors and/or plasmas may be different. In some embodiments, the CFD deposited capping layer may employ one or more CFD nitride or oxynitride film layers.

After the capping layer was deposited, a conformal stack containing the dopant source according to FIG. 6 was built/deposited. In some embodiments, for example, the conformal stack may be schematically similar to the conformal stack shown schematically in FIG. 3 where the dopant source is B ₂ O ₃ and the dielectric is one or more oxides. Finally, with the conformal stack fully assembled in operation N, the lower substrate may be doped by driving the dopant from the conformal stack into the lower semiconductor substrate. In some embodiments, this may be accomplished by a heat mediated diffusion process, for example, as detailed below.

Finally, another stack strategy that may be used to combine the CFD dielectric (eg, silicon oxide) layer deposition with the ALD dopant layer deposition is to include “alloy layers” as shown in FIG. 4(d). It is what constitutes the "stack". For example, the alloy layers may be constructed by having a dielectric precursor BTBAS and a dopant precursor TMB that co-flow and oxidize simultaneously in the reaction chamber. That is, in some embodiments, the alloy layer introduces both precursors onto the substrate (or adhered to the substrate) under conditions that introduce a dopant precursor and a dielectric precursor into the reaction chamber and the dopant precursor and the dielectric precursor form an adsorption limiting layer. On the material), and may be formed by reacting the adsorbed dopant precursor and the adsorbed dielectric precursor to form an alloy layer. In certain such embodiments, the alloy layer is formed by reacting the adsorbed dielectric precursor with a dopant and dielectric precursors and a third reactant, which may be an oxidant introduced into the reaction chamber. In certain such embodiments, the reaction of the adsorbed dielectric precursor and the oxidant may include plasma activation. In other embodiments, the “alloy layers” shown in FIG. 4(d) deposits the nanolaminates or monolayers shown in FIGS. 4(b) and 4(c), respectively, and (usually at higher temperatures , But in some embodiments may be formed by annealing the layers (at a temperature below the "drive" temperature to form "alloy layers"), which results in a composite homogeneous glass layer.

Dopant driving from the deposited conformal film stack into the underlying substrate

After the conformal film stack is completely deposited, the conformal film stack may be used as a source of dopant species for nearby semiconductor structures. This may be achieved by driving the dopant from the deposited film to the device structure. In various embodiments, driving is accomplished by a heat mediated diffusion process such as annealing. In some cases, laser spike annealing may be employed, particularly in the case of employing ultraslow junctions.

Devices

Any suitable device may be employed to manufacture and use the ALD film layers containing the conformal dopant source described herein. For example, US Patent Application No. The apparatus described in 13/224,240 may be used. This patent application is incorporated herein by reference in its entirety for all purposes.

In some embodiments, a system controller (which may include one or more physical or logical controllers) controls all activities of the process tool used in the dopant ALD cycle or dielectric CFD cycle. The system controller runs system control software on one or more processors. System control software includes timing, mixture of gases, chamber and/or station pressure, chamber and/or station temperature, wafer temperature, target power levels, RF power levels, substrate pedestal, chuck and/or susceptor ( susceptor) positions, and instructions to control other parameters of a particular ALD/CFD process performed by the process tool. The system control software may be configured in any suitable way. For example, various process tool component subroutines or control objects may be created to control the operation of process tool components necessary to execute various process tool processes. System control software may be coded in any suitable computer readable programming language.

In some embodiments, the system control software includes input/output control (IOC) sequencing instructions for controlling the various parameters described above. For example, each phase of the ALD/CFD process may contain one or more instructions for execution by the system controller. Instructions for setting process conditions for the ALD/CFD process phase may be included in the corresponding ALD/CFD recipe phase. In some embodiments, ALD/CFD recipe phases may be arranged sequentially, such that all instructions for the ALD/CFD process phase are executed concurrently with the process phase.

Other computer software and/or programs may be employed in some embodiments. Examples of programs for this purpose or sections of programs include a substrate positioning program, a process gas control program, a pressure control program, a heater control program and a plasma control program.

The substrate positioning program may include program code for process tool components used to load the substrate on the pedestal and control the spacing between the substrate and other parts of the process tool.

The process gas control program may include code for controlling gas composition and flow rates and, optionally, code for flowing gas into one or more process stations prior to deposition to stabilize pressure in the process station. The pressure control program may include code for controlling pressure at the process station, for example, by regulating throttle valves in the process station's exhaust system, gas flow into the process station, and the like.

The heater control program may include code for controlling the current to the heating unit used to heat the substrate. Alternatively, the heater control program may control the supply of heat transfer gas (such as helium) to the substrate.

The plasma control program may include code to set RF power levels applied to process electrodes at one or more process stations.

In some embodiments, there may be a user interface associated with the system controller. The user interface may include a display screen, graphics software displays and/or process conditions of the apparatus, and user input devices, such as pointing devices, keyboards, touch screens, microphones, and the like.

In some embodiments, parameters adjusted by the system controller can be related to process conditions. Non-limiting examples include process gas composition and flow rate, temperature, pressure, plasma conditions (eg, RF bias power levels), pressure, temperature, and the like. These parameters are provided to the user in the form of a recipe, which may also be entered using a user interface.

Signals for monitoring the process can be provided by analog and/or digital input connections of the system controller from various process tool sensors. Signals for controlling the process may be output on analog and digital output connections of the process tool. Non-limiting examples of process tool sensors that may be monitored include mass flow controllers, pressure sensors (eg, manometers), thermocouples, and the like. Properly programmed feedback and control algorithms may be used in conjunction with data from these sensors to maintain process conditions.

The system controller may provide program instructions for implementing the dopant ALD and dielectric CFD cycles and processes described above. Program instructions may control various process parameters, such as DC power level, RF bias power level, pressure, temperature, and the like. Instructions may control these parameters to operate in situ deposition of conformal film stacks in accordance with various embodiments described herein.

Thus, the system controller for providing program instructions to the device for doping the substrate includes instructions for detecting the presence of the substrate on the substrate holder in the reaction chamber, a material with a dopant precursor on the substrate or adhered to the substrate. Instructions for operating one or more dopant precursor gas inlets to introduce the dopant precursor into the reaction chamber to adsorb, instructions for operating one or more outlets to evacuate the non-adsorbed dopant precursor from the reaction chamber, and dopant source May have machine readable code that may include instructions to react the adsorbed dopant precursor to form a film layer. In some embodiments, instructions for reacting the adsorbed dopant precursor include instructions for operating the RF generator to excite the plasma that causes the adsorbed dopant precursor to react. In some embodiments, the machine readable code may further include instructions to drive a portion of the dopant source from the film into the substrate, and in certain such embodiments, these “drive” instructions heat the film It may further include instructions to operate the heater to cause thermally mediated diffusion of the dopant from the film into the substrate.

The apparatus/process described above may be used in conjunction with lithographic patterning tools or processes, for example, for the manufacture or manufacture of semiconductor devices, displays, LEDs, photovoltaic panels, and the like. Typically, but not necessarily, these tools/processes will be used or implemented together in an ordinary production facility. Lithographic patterning of a film typically includes some or all of the following actions, each action being made possible by a number of possible tools: (1) a workpiece, ie a spin-on or spray-on tool on a substrate. Photoresist coating using; (2) photoresist curing using a hot plate or furnace or UV curing tool; (3) photoresist exposure to visible or UV or x-ray light using a tool such as a wafer stepper; (4) resist development using a tool such as a wet bench to selectively remove and pattern the resist; (5) transfer of the resist pattern to the underlying film or workpiece by using a dry or plasma assisted etching tool; And (6) removal of the resist using a tool such as an RF or microwave plasma resist stripper.

Experiments and examples

7 compares (WiW) thickness non-uniformity (NU) in a wafer between various B ₂ O ₃ stacks deposited using various different methods. Each stack includes conformal film layers of ALD deposited dopant source B ₂ O ₃ interposed with dielectric CFD layers. The first four B ₂ O ₃ stacks, MOD1 to MOD4, were deposited through CVD processes with varying deposition temperatures and B ₂ H ₆ flow rates, which stacks exhibit a NU range of ˜8-16%. The two B ₂ O ₃ stacks deposited through ALD, with the ALD1 process employing an inert plasma and the ALD2 process employing an oxidized plasma, exhibit a sharply improved thickness NU range of ˜1.3-1.6%. Note that the bars of the “% STDDEV” label shown in the plot of FIG. 7 represent the percent standard deviation at NU measured across multiple wafers.

7 also shows the reduction in WiW NU achievable by boron containing conformal films formed using ALD, relative to boron containing conformal films formed via CVD. In FIG. 8, the results of 13 point Fourier transform infrared spectroscopy (FTIR) measurements of B ₂ O ₃ films formed using ALD versus CFD are shown. Results for the CVD film are plotted on the left graph and results for the ALD films are plotted on the right. Two curves occupy each graph, one corresponding to the FTIR adsorption spectrum taken at the center of the wafer, and the other to the adsorption spectrum taken near the wafer edge. For a CVD film, a visible difference in center and edge adsorption curves (especially near the boron-oxygen stretching vibrations) can be seen in FIG. 8 corresponding to 10.3% NU. Conversely, the center and edge adsorption curves taken from the ALD membrane almost overlap, exhibiting only 2.5% NU, again showing improved WiW uniformity achievable with ALD membranes. These improvements are mainly due to the substantially perfect surface saturation potentially achievable through ALD processes, especially at thickness regimes of interest (about 5-10 nm).

Another method of measuring in-wafer non-uniformity (WiW NU) at film stack thickness is to drive the dopant from the stack into the silicon substrate (e.g., by spike annealing) and to measure the resulting sheet resistance (R _s ) of the silicon substrate. will be. Since the amount of dopant available for driving into the substrate correlates with the stack thickness, uniform sheet resistance indicates uniform stack thickness. In addition, WiW uniformity of dopant concentration after annealing is clearly an important consideration in device fabrication. Table 1 shows the average sheet resistance of the silicon substrate after stack deposition and spike annealing corresponding to boron-containing stacks (CVD-B) deposited using CVD methodology and boron-containing stacks (ALD-B) deposited using ALD methodology. (Mean R _s ) and percent standard deviation (% Std Dev) are listed. Table 1 shows that the ALD film exhibits a sharply improved WiW NU for sheet resistance compared to the CVD film, particularly within the desired dopant drive values typically employed in semiconductor fabrication, ie 100-5000 ohm/sq. With ALD, in-wafer variation of average sheet resistance can be achieved below a standard deviation of less than 4%, as compared to a standard deviation of almost 195% when using CVD.

Table 2 shows the ranges in which the various stack strategies described above may be used to adjust and control the dopant concentration. In this particular example, boron concentration was measured in conformal stacks approximately 100 mm thick of ALD B ₂ O ₃ and CFD silicon oxide.

Due to this, by employing different stack strategies, the dopant concentration may be effectively controlled in a regime over a two-digit number. Stack strategies and stack engineering, as well as adjustment of the capping layer chemical engineering, may also be used to adjust and control the sheet resistance and the corresponding degree of WiW NU. For example, Table 3 shows the effect of controlling the ratio and sequence of ALD dopant source layer to CFD oxide layer deposition. Specifically, Table 3 shows the effect of controlling the layer ratio and sequence on the thickness non-uniformity (Thx NU) and sheet resistance WiW non-uniformity (R _s (drive) NU) of the ALD films as they are deposited. Note that the "2:2" ratio in the table corresponding to the configuration with the lowest sheet resistance WiW NU means that two SiO ₂ layers, etc. were deposited after the two B ₂ O ₃ layers were deposited. Note that these ALD film stacks were deposited at approximately 200°C, which resulted in consistently lower R _s NUs compared to ALD film stacks deposited at higher temperatures, such as 400°C.

Table 4 shows that by changing the capping layer chemistry, WiW NU may be improved from 41% to 21%.

Without being limited to a particular theory, back-diffusion of the dopant source (i.e., diffusion of the dopant away from the membrane-substrate interface) is blocked by the capping layer by depositing a suitable capping layer, so that the dopant in the stack It is assumed that it is possible to effectively simulate the infinite storage of. 8 schematically illustrates a conformal film stack with alternating ALD dopant source and oxide layers deposited on a silicon substrate with a capping layer deposited over the pattern.

The dopant uniformity in the underlying substrate after delivery from the conformal film stack through spike annealing is illustrated by the boron concentration profiles shown in FIGS. 9 and 10. Both figures plot boron concentration in the underlying silicon substrate as a function of substrate depth measured at both the center and edge of the substrate. 9 shows the results of doping a substrate with a 2:1 ratio stack of Table 3 (WiW NU is 13.2%). In the figure, some slight differences between center and edge dopant concentration profiles as a function of depth are clearly seen. 10 shows the results of doping a substrate with a 2:2 ratio stack of Table 3 (where WiW NU is 5.3%). As shown in the figure, for a 2:2 stack, boron concentration profiles nearly overlap to a depth of approximately 200 mm 2. Both figures show a high concentration boron of around 1E22 atoms/cm ³ near the substrate surface, which shows good transfer from conformal film stacks. The total boron dose is in the range of 8.4E14 atoms/cm ² to 4E15 atoms/cm ² .

As discussed above, an arsenic or phosphorus-based dopant source may also be used in the conformal film stack to dope the underlying semiconductor substrate. For example, FIG. 11(a) is a schematic diagram of a sequence of operations for doping a lower semiconductor substrate using a conformal stack having an arsenic silicate glass (ASG) based dopant layer. In this particular embodiment, the ASG-based conformal stack is formed by first depositing an ASG conformal film through an ALD process, and then depositing an undoped silicate glass (USG) capping layer through a CFD process. Note that, depending on the embodiment, various arsenic or phosphorus-based conformal films may be combined with various types of capping layers, such as various types of capping layers disclosed herein. It is also noted that test vehicles similar to those schematically shown in FIG. 11(a) may be employed using phosphorus silicate glass (PSG) or boron silicate glass (BSG).

With the stack in place, thermal annealing is performed to drive the arsenic dopant into the underlying substrate. 11(b) schematically shows the annealing temperature profile. In some embodiments, the temperature ranges for annealing may be between 800° C. and 1100° C. or higher, or between about 850° C. and 1000° C. or higher, or between about 875° C. and 925° C. or higher. In some embodiments, the annealing temperature and the annealing time (ie, the period for maintaining the annealing temperature) may be selected to achieve a specific target sheet resistance at the lower substrate. In some embodiments, an annealing temperature of approximately 900° C. and an annealing time of less than 5 seconds may be selected to achieve a sheet resistance of approximately 600-2000 ohm/sq. 11(b) schematically, through an annealing process, the temperature is ramped upwards (and downwards from the maximum temperature) to a maximum temperature for some duration defining the temperature profile characteristics of the annealing. Again, in some embodiments, this temperature profile may be selected to derive the desired sheet resistance at the lower substrate.

After annealing results in the transfer of dopant from the conformal stack into the substrate, in some embodiments, the stack is removed through a stripping operation. In some embodiments, as shown in FIG. 11(a), the stripping operation involves treatment of a conformal stack with dilute hydrofluoric acid (HF).

Other embodiments

Multiple variations of this baseline process may be realized. Some of these variants have an increase in the amount of dopant available for diffusion into adjacent semiconductor structures as the goal. Other variations are designed to control the flow rate of the dopant delivered from the source film into the nearby semiconductor structure. Other variations control the direction in which the dopant species diffuse. Frequently, it is desirable to help diffuse the dopant towards the device structure and away from the opposite side of the membrane. Certain variations are described in U.S. Patent Application No. 13/242,084, previously incorporated by reference.

In addition, it should be understood that the configurations and/or approaches described herein are exemplary in nature, and that these particular embodiments or examples should not be considered in a limiting sense because various modifications are possible. The specific routines or methods described herein may represent one or more of any number of processing strategies. Thus, the various acts illustrated may be performed in parallel, in other sequences, in the illustrated sequence, or may be omitted in some cases. Likewise, the order of the above-described processes may be changed.

Claims (47)

A method of doping a patterned substrate in a reaction chamber,
Forming a first conformal film layer comprising a dopant source comprising a dopant that is boron, either directly on a surface of a patterned substrate having three-dimensional features or on a material adhered to the surface,
(a) introducing a dopant precursor that is an alkyl borate into the reaction chamber;
(b) adsorbing the dopant precursor directly on the surface or on a material adhered to the surface under conditions where the dopant precursor forms an adsorption-limited layer; And
(c) forming the first conformal film layer, comprising reacting the adsorbed dopant precursor to form the dopant source; And
After forming the first conformal film layer, forming a second conformal film layer including the dopant source, the second conformal film comprising the steps (a) to (c) Forming a layer;
After forming the second conformal film layer, forming a third conformal film layer comprising a dielectric material,
(i) introducing a dielectric precursor into the reaction chamber;
(ii) adsorbing the dielectric precursor onto a material adhered to the patterned substrate under conditions to form an adsorption limiting layer comprising the adsorbed dielectric precursor; And
(iii) forming the third conformal film layer, comprising reacting the adsorbed dielectric precursor to form the dielectric material;
After forming the third conformal film layer, forming a fourth conformal film layer comprising a dielectric material, comprising the steps (i) to (iii), the fourth conformal film Forming a layer;
After forming the fourth conformal film layer, forming a fifth conformal film layer including the dopant source, the fifth conformal film comprising the steps (a) to (c) Forming a layer;
After forming the fifth conformal film layer, forming a sixth conformal film layer including the dopant source, the sixth conformal film comprising the steps (a) to (c) Forming a layer; And
From the first conformal film layer, the second conformal film layer, the fifth conformal film layer and the sixth conformal film layer to form a conformal doping profile on the patterned substrate A method of doping a patterned substrate, comprising driving a portion of the dopant into a patterned substrate. According to claim 1,
The step of forming the first conformal film layer, the second conformal film layer, the fifth conformal film layer, and the sixth conformal film layer includes atomic layer deposition. Method of doping a substrate. According to claim 2,
The step of forming the first conformal film layer, the second conformal film layer, the fifth conformal film layer and the sixth conformal film layer is: (d) removing the non-adsorbed dopant precursor from the reaction chamber And further comprising the step of doping. The method of claim 3,
Wherein step (d) occurs after step (a) but before step (c). The method of claim 4,
The step (d) includes pumping a non-adsorbed dopant precursor from the reaction chamber by pumping the reaction chamber to a base pressure using a vacuum pump. The method of claim 4,
The step (d) comprises purging the reaction chamber with an inert gas, the method of doping a patterned substrate. According to claim 1,
The step (c) is a method of doping a patterned substrate comprising activation using plasma. The method of claim 7,
Wherein the plasma is an oxidative plasma. The method of claim 7,
Wherein the plasma is an inert plasma. According to claim 1,
Driving a portion of the dopant from the first conformal film layer, the second conformal film layer, the fifth conformal film layer, and the sixth conformal film layer comprises a heat mediated diffusion process. Method of doping a substrate. The method of claim 10,
The method of doping a patterned substrate, wherein the thermally mediated diffusion process involves annealing. The method of claim 11,
The annealing is laser spike annealing, a method of doping a patterned substrate. According to claim 1,
Wherein the alkyl borate is trimethyl borate. According to claim 1,
Wherein the dopant source is boron oxide or boron oxyhydride. The method of claim 14,
The boron oxide is B ₂ O ₃ , a method of doping a patterned substrate. According to claim 1,
The method of doping a patterned substrate, wherein the dielectric material of the second conformal film layer is SiO ₂ . According to claim 1,
After forming the sixth conformal film layer, forming a seventh conformal film layer containing the dielectric material, the step (i) to the step (iii) comprising the seventh conformal film Forming a film layer;
After forming the seventh conformal film layer, forming an eighth conformal film layer comprising a dielectric material, the step (i) to the step (iii) comprising the eighth conformal film Forming a layer;
After forming the eighth conformal film layer, forming a ninth conformal film layer including the dopant source, the ninth conformal film comprising the steps (a) to (c) Forming a layer;
After forming the ninth conformal film layer, forming a tenth conformal film layer including the dopant source, the tenth conformal film comprising steps (a) to (c) Forming a layer; And
And driving a portion of the dopant from the fifth conformal film layer into the patterned substrate to form a conformal doping profile on the patterned substrate. According to claim 1,
And forming a seventh conformal film layer that is a capping layer, the capping layer being the outermost film layer of the first to sixth conformal film layers to the patterned substrate. To doped substrate. The method of claim 18,
The method for doping a patterned substrate, wherein the capping layer comprises SiO ₂ . According to claim 1,
The step (c) comprises exposing the adsorbed dopant precursor to an oxidizing agent, the method of doping a patterned substrate. The method of claim 20,
The method of doping a patterned substrate, wherein the oxidizing agent is elemental oxygen, nitrous oxide, water, alkyl alcohol, carbon monoxide or carbon dioxide. According to claim 1,
The step (iii) is a method of doping a patterned substrate comprising activation using plasma. According to claim 1,
The dielectric precursor
Alkylamino silane (SiH _x (NR ₂ ) _4-x ) (where x = 1 to 3, R includes an alkyl group) and halosilane (SiH _x Y _4-x ) (where x = 1 to 3 And Y is selected from the group consisting of Cl, Br, and I). According to claim 1,
The dielectric precursor is BTBAS, a method of doping a patterned substrate. According to claim 1,
A method of doping a patterned substrate, wherein each of the first conformal film layer to the sixth conformal film layer is a monolayer. According to claim 1,
A method of doping a patterned substrate, wherein the average thickness of each of the first conformal film layer to the sixth conformal film layer is between 0.1 and 2 Angstroms. According to claim 1,
A method of doping a patterned substrate, wherein at least one of the three-dimensional features has a width of 40 nanometers or less. According to claim 1,
A method of doping a patterned substrate, wherein the average concentration of dopants on the first conformal film layer to the sixth conformal film layer is between 0.01 and 10% by weight. A method of doping a patterned substrate in a reaction chamber,
Forming an alloy comprising a dopant source comprising a dopant and a dielectric, either directly on the surface of the patterned substrate having three-dimensional features or on a material adhered to the surface,
The pattern under conditions that introduce a dopant precursor and a dielectric precursor into the reaction chamber and form an adsorption-limited layer comprising the dopant precursor and the adsorbed dielectric precursor adsorbed by the dopant precursor and the dielectric precursor Co-adsorbing the dopant precursor and the dielectric precursor on a substrate or on a material adhered to the patterned substrate, and
Forming the alloy, comprising reacting the adsorbed dopant precursor and the adsorbed dielectric precursor to form the dopant source and the alloy having the dopant source; And
And driving a portion of the dopant from the alloy into the patterned substrate to form a conformal doping profile on the patterned substrate. The method of claim 29,
Forming the alloy further comprises introducing a third reactant into the reaction chamber and reacting the third reactant with the adsorbed dielectric precursor. The method of claim 30,
The third reactant is an oxidant, a method of doping a patterned substrate. The method of claim 31,
The step of reacting the third reactant with the adsorbed dielectric precursor further comprises activation using plasma, a method of doping a patterned substrate. An apparatus for doping a substrate,
Reaction chamber;
A substrate holder in the reaction chamber;
One or more dopant precursor gas inlets connected to the reaction chamber;
One or more vacuum pumps;
One or more gas outlets connecting the reaction chamber to the one or more vacuum pumps; And
A controller having machine readable code, the machine readable code comprising:
Instructions for determining that a substrate is present on the substrate holder;
Instructions causing the formation of a first conformal film layer,
(a) operating the one or more dopant precursor gas inlets to introduce the dopant precursor into the reaction chamber such that the dopant precursor is adsorbed onto the substrate or on a material adhered to the substrate to form an adsorbed dopant precursor. Commands for;
(b) instructions for operating the one or more gas outlets to evacuate a non-adsorbed dopant precursor from the reaction chamber; And
(c) instructions for causing the formation of the first conformal film layer, including instructions for reacting the adsorbed dopant precursor to form a film layer containing a dopant source;
Instructions for causing the formation of a second conformal film layer to be executed after executing the instructions for forming the first conformal film layer, comprising the instructions (a) to (c), the second Instructions for causing the formation of a conformal film layer;
Instructions for causing the formation of a third conformal film layer to be executed after the instructions for forming the second conformal film layer,
(i) instructions to trigger operation of the one or more dopant precursor gas inlets to introduce the dielectric precursor into the reaction chamber such that the dielectric precursor is adsorbed onto a material adhered to the substrate to form an adsorbed dielectric precursor. ;
(ii) instructions to trigger operation of the one or more gas outlets to discharge a non-adsorbing dielectric precursor from the reaction chamber; And
(iii) instructions for triggering the formation of the third conformal film layer, including instructions for triggering the reaction of the adsorbed dielectric precursor to form a film layer containing a dielectric material; And
Instructions for causing the formation of a fourth conformal film layer to be executed after the instructions for forming the third conformal film layer, comprising the instructions (i) to the instruction (iii), the fourth conformal An apparatus for doping a substrate, comprising instructions for causing the formation of a film layer. The method of claim 33,
Further comprising an RF generator configured to excite the plasma in the reaction chamber, and (c) instructions for triggering the reaction of the adsorbed dopant precursor to excite the plasma causing the adsorbed dopant precursor to react. An apparatus for doping a substrate, comprising instructions for operating an RF generator. The method of claim 33,
And the machine readable code further comprises instructions for causing driving of a portion of the dopant source from the first conformal film layer or the third conformal film layer into the substrate. The method of claim 35,
Further comprising a heater configured to heat the first conformal film layer or the third conformal film layer containing the dopant source, and instructions for causing driving of a portion of the dopant into the substrate, the first Of the heater that heats the conformal film layer or the third conformal film layer to cause thermally mediated diffusion of the dopant from the first conformal film layer or the third conformal film layer into the substrate. An apparatus for doping a substrate, comprising instructions for causing an action. The method of claim 29,
The dopant source comprises arsenic dopant,
Wherein the dopant precursor is selected from the group consisting of alkylarsine, alkoxyarsine, and aminoarsine chemical groups. The method of claim 37,
The dopant source is an adeno-silicate, arsenic doped silicate glass, arsenic oxide or arsenic oxyhydride, a method of doping a patterned substrate. The method of claim 37,
The dopant precursor is arsine, triethyl arsenate, trimethyl arsine, triethyl arsine, triphenyl arsine, triphenyl arsine oxide, ethylene bis (diphenyl arsine), tris (dimethylamino) arsine, Or a method of doping a patterned substrate, which is an arsenic-containing compound having the formula As(OR) ₃ (wherein R is -CH ₃ or -C ₂ H ₅ ). The method of claim 38,
Wherein the dopant source is As ₂ O ₃ and/or As ₂ O ₅ , a method of doping a patterned substrate. The method of claim 23 or 29,
The dielectric precursor is diisopropylaminosilane, a method of doping a patterned substrate. The method of claim 23 or 29,
The dielectric precursor is bisdiethylaminosilane, a method of doping a patterned substrate. The method of claim 23 or 29,
The method of doping a patterned substrate, wherein the dielectric precursor is x and R is propyl alkylamino silane (SiH _x (NR ₂ ) _4-x ). delete delete delete delete

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