Method for low temperature growth of thick oxide films of thermal oxide quality

Abstract

Embodiments described herein generally relate to methods of forming low-k dielectric materials on semiconductor substrates. More specifically, embodiments described herein relate to methods of forming silicon oxide films at high pressure and low temperature. The method of forming the silicon oxide film comprises the steps of loading a substrate having a silicon-containing film formed thereon into a processing region of a high pressure vessel. The method further comprises the steps of forming the silicon oxide film on the silicon-containing film. The step of forming the silicon oxide film on the silicon-containing film comprises the steps of exposing the silicon-containing film to an oxidizing medium including an amine additive at a pressure greater than about 1 bar, and maintaining the high pressure vessel at a temperature between about 100 degrees Celsius and about 550 degrees Celsius.

Description

Technical Field

[0001] Embodiments described herein generally relate to methods for forming low-k dielectric materials on semiconductor substrates. More specifically, embodiments described herein relate to methods for forming silicon oxide films at high pressure and low temperature using an oxidizing medium including an additive. Background Art

[0002] The formation of semiconductor devices (such as memory devices, logic devices, microprocessors, etc.) involves depositing low-k dielectric films over semiconductor substrates. Low-k dielectric films are used to manufacture circuits of devices. Current dry or wet silicon oxidation techniques are typically performed at temperatures above 800 degrees Celsius. However, the materials deposited on the semiconductor substrate may not be able to withstand temperatures greater than 800 degrees Celsius. As a result, low-k dielectric films may not be deposited at temperatures greater than 800 degrees Celsius of thermal budget, and films deposited within the thermal budget are typically plagued by poor quality. In addition, current dry or wet silicon oxidation techniques cannot deposit high-quality low-k dielectric films having a thickness greater than 100 angstroms.

[0003] Therefore, a need exists for a method of depositing high quality low-k dielectric films at temperatures that meet thermal budget targets. Summary of the invention

[0004] Embodiments described herein generally relate to methods of forming low-k dielectric materials on semiconductor substrates. More specifically, embodiments described herein relate to methods of forming a silicon oxide film at high pressure and low temperature. The method of forming the silicon oxide film comprises the steps of loading a substrate having a silicon-containing film formed thereon into a processing region of a high pressure vessel. The method further comprises the steps of forming the silicon oxide film on the silicon-containing film. The step of forming the silicon oxide film on the silicon-containing film comprises the steps of exposing the silicon-containing film to an oxidizing medium including an amine additive at a pressure greater than about 1 bar; and maintaining the high pressure vessel at a temperature between about 100 degrees Celsius and about 550 degrees Celsius.

[0005] A method for forming a silicon oxide film includes the steps of: loading a substrate having a silicon-containing film deposited thereon into a processing region of a high pressure vessel; and forming the silicon oxide film on the silicon-containing film. The step of forming the silicon oxide film on the silicon-containing film includes the steps of: exposing the silicon-containing film to an oxidizing medium including an amine additive at a pressure greater than about 1 bar; and maintaining the high pressure vessel at a temperature between about 100 degrees Celsius and about 550 degrees Celsius.

[0006] A method for forming a conformal silicon oxide film includes the steps of: depositing a silicon-containing film on a substrate including a plurality of vias. The silicon-containing film is deposited on each exposed surface of the substrate and the plurality of vias. The method further includes the steps of: loading the substrate with the silicon-containing film deposited thereon into a processing region of a high-pressure vessel; and forming a conformal silicon oxide film on the silicon-containing film. The step of forming a conformal silicon oxide film on the silicon-containing film includes the steps of: exposing the silicon-containing film to an oxidizing medium including an amine additive, wherein the oxidizing medium includes about 1,000 ppm to about 20,000 ppm of the amine additive; and maintaining the high-pressure vessel at a temperature between about 100 degrees Celsius and about 550 degrees Celsius and at a pressure between about 1 bar to about 65 bar.

[0007] A method for forming a silicon oxide film includes the steps of: loading a substrate having a silicon-containing film deposited thereon into a processing region of a high pressure vessel; and forming the silicon oxide film on the silicon-containing film. The step of forming the silicon oxide film on the silicon-containing film includes the steps of: exposing the silicon-containing film to an oxidizing medium including ammonia, wherein the oxidizing medium is selected from the group consisting of steam, oxygen, and peroxide; and maintaining the high pressure vessel at a temperature between about 400 degrees Celsius and about 505 degrees Celsius and at a pressure greater than about 10 bar. The silicon oxide film has a uniform thickness between about 100 angstroms and about 400 angstroms. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to understand in detail the manner in which the above-mentioned features of the present disclosure are achieved, a more specific description of the present disclosure briefly summarized above may be obtained by referring to the embodiments, some of which are shown in the accompanying drawings. However, it should be noted that the accompanying drawings only show exemplary embodiments and therefore should not be considered as limiting the scope thereof, and other equivalent embodiments may be allowed.

[0009] Figure 1 Depicted is a simplified front cross-sectional view of one example of a high pressure vessel that may be used to implement one or more embodiments described herein.

[0010] Figure 2A A semiconductor device is shown having a silicon-containing film deposited thereon according to embodiments disclosed herein.

[0011] Figure 2B-2D Various views of a semiconductor device having a conformal and uniform silicon oxide film formed thereon according to embodiments disclosed herein are shown.

[0012] Figure 3 is a flow chart showing a method of forming a conformal silicon oxide film according to one embodiment.

[0013] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation. DETAILED DESCRIPTION

[0014] Embodiments described herein generally relate to methods of forming low-k dielectric materials on semiconductor substrates. More specifically, embodiments described herein relate to methods of forming a silicon oxide film at high pressure and low temperature. The method of forming the silicon oxide film comprises the steps of loading a substrate having a silicon-containing film formed thereon into a processing region of a high pressure vessel. The method further comprises the steps of forming the silicon oxide film on the silicon-containing film. The step of forming the silicon oxide film on the silicon-containing film comprises the steps of exposing the silicon-containing film to an oxidizing medium including an amine additive at a pressure greater than about 1 bar, and maintaining the high pressure vessel at a temperature between about 100 degrees Celsius and about 550 degrees Celsius.

[0015] The embodiments described herein will be described below with reference to high pressure oxidation processes that can be performed using a high pressure oxidation system. Figure 1 In the present invention, the device descriptions described herein are illustrative and should not be read or interpreted as limiting the scope of the embodiments described herein.

[0016] Figure 1 1 is a simplified front cross-sectional view of a high pressure vessel 100 for high pressure annealing processing. The high pressure vessel 100 has a body 110 having an outer surface 112 and an inner surface 113 enclosing a processing area 115. In a process such as Figure 1 In some embodiments, the body 110 has a circular cross-section, but in other embodiments, the cross-section of the body 110 can be rectangular or any closed shape. The outer surface 112 of the body 110 can be made of corrosion resistant steel (CRS), such as but not limited to stainless steel. In one embodiment, the inner surface 113 of the body 110 is made of a nickel-based steel alloy that exhibits high corrosion resistance (such as but not limited to stainless steel). ) is made.

[0017] The high pressure vessel 100 has a door 120 configured to sealably enclose a processing area 115 within the body 110 so that the processing area 115 is accessible when the door 120 is open. A high pressure seal 122 is used to seal the door 120 to the body 110 so as to seal the processing area 115 for processing. The high pressure seal 122 may be made of a polymer, such as, but not limited to, a perfluoroelastomer. A cooling channel 124 is provided adjacent to the high pressure seal 122 on the door 120 so as to maintain the high pressure seal 122 below the maximum safe operating temperature of the high pressure seal 122 during processing. A coolant (such as, but not limited to, an inert, dielectric, and / or high performance heat transfer fluid) may be circulated within the cooling channel 124 to maintain the high pressure seal 122 at a temperature between about 150 degrees Celsius and about 250 degrees Celsius. The flow of the coolant within the cooling channel 124 is controlled by the controller 180 through feedback received from the temperature sensor 116 or a flow sensor (not shown).

[0018] The high pressure vessel 100 has a port 117 passing through the body 110. The port 117 has a tube 118 passing therethrough, and the tube 118 is coupled to a heater 119. One end of the tube 118 is connected to the processing area 115. The other end of the tube 118 is bifurcated into an inlet conduit 157 and an outlet conduit 161. The inlet conduit 157 is fluidly connected to the gas panel 150 via an isolation valve 155. The inlet conduit 157 is coupled to the heater 158. The outlet conduit 161 is fluidly connected to the condenser 160 via an isolation valve 165. The outlet conduit 161 is coupled to the heater 162. The heaters 119, 158, and 162 are configured to maintain the process gas (such as an oxidizing medium) flowing through the tube 118, the inlet conduit 157, and the outlet conduit 161, respectively, at a temperature between the condensation point of the process gas and about 250 degrees Celsius. The heaters 119, 158, and 162 are powered by a power supply 145.

[0019] The gas panel 150 is configured to provide a process gas (such as an oxidizing medium) under pressure into an inlet conduit 157 for transmission into the processing area 115 through the tube 118. The oxidizing medium includes an amine additive. The pressure of the process gas introduced into the processing area 115 is monitored by a pressure sensor 114 coupled to the body 110. The condenser 160 is fluidly coupled to the cooling fluid and is configured to condense the gaseous product flowing through the outlet conduit 161 after being removed from the processing area 115 via the tube 118. The condenser 160 converts the gaseous product from the gas phase to the liquid phase. The pump 170 is fluidly connected to the condenser 160 and extracts the liquefied product from the condenser 160. The operation of the gas panel 150, the condenser 160 and the pump 170 is controlled by the controller 180.

[0020] Isolation valves 155 and 165 are configured to allow only one fluid to flow through tube 118 into process region 115 at a time. When isolation valve 155 is open, isolation valve 165 is closed, allowing process gas flowing through inlet conduit 157 to enter process region 115, thereby preventing process gas from flowing into condenser 160. On the other hand, when isolation valve 165 is open, isolation valve 155 is closed, allowing gaseous products to be removed from process region 115 and flow through outlet conduit 161, thereby preventing gaseous products from flowing into gas panel 150.

[0021] One or more heaters 140a, 140b (collectively 140) are disposed on the body 110 and are configured to heat the processing region 115 within the high pressure vessel 100. In some embodiments, as Figure 1 1, the heater 140 is disposed on the outer surface 112 of the body 110, although in other embodiments, the heater 140 may be disposed on the inner surface 113 of the body 110. Each of the heaters 140 may be a resistive coil, a lamp, a ceramic heater, a graphite-based carbon fiber composite (CFC) heater, a stainless steel heater, or an aluminum heater. The heaters 140 are powered by a power source 145. The power supply to the heaters 140 is controlled by the controller 180 through feedback received from the temperature sensor 116. The temperature sensor 116 is coupled to the body 110 and monitors the temperature of the processing area 115.

[0022] A cassette 130 coupled to an actuator (not shown) is moved into and out of the processing region 115. The cassette 130 has a top surface 132, a bottom surface 134, and a wall 136. The wall 136 of the cassette 130 has a plurality of substrate storage slots 138. Each substrate storage slot 138 is evenly spaced along the wall 136 of the cassette 130. Each substrate storage slot 138 is configured to hold a substrate 135 therein. The cassette 130 may have up to fifty substrate storage slots 138 for holding substrates 135. The cassette 130 provides an efficient carrier for moving a plurality of substrates 135 into and out of the high pressure vessel 100 and for processing a plurality of substrates 135 in the processing region 115.

[0023] The controller 180 controls the operation of the high pressure vessel 100. The controller 180 controls the operation of the gas panel 150, the condenser 160, the pump 170, the isolation valve 155 and the isolation valve 165, and the power supply 145. The controller 180 is also communicatively connected to the temperature sensor 116, the pressure sensor 114, and the cooling channel 124. The controller 180 includes a central processing unit (CPU) 182, a memory 184, and support circuits 186. The CPU 182 can be any form of general purpose computer processor that can be used in an industrial environment. The memory 184 can be a random access memory, a read-only memory, a floppy disk or a hard disk drive, or other form of digital storage. The support circuits 186 are conventionally coupled to the CPU 182 and can include cache, clock circuits, input / output systems, power supplies, and the like.

[0024] The high pressure vessel 100 provides a convenient chamber to perform a method of forming a silicon oxide film on a plurality of substrates 135 at a temperature of 550 degrees Celsius or less. The heater 140 is powered on to preheat the high pressure vessel 100 and maintain the processing area 115 at a temperature of about 550 degrees Celsius or less. At the same time, the heaters 119, 158, and 162 are powered on to preheat the tube 118, the inlet conduit 157, and the outlet conduit 161, respectively.

[0025] A plurality of substrates 135 are loaded on the cassette 130. The door 120 of the high pressure vessel 100 is opened to move the cassette 130 into the processing area 115. The door 120 is then sealed closed to turn the high pressure vessel 100 into a high pressure vessel. Once the door 120 is closed, the high pressure seal 122 ensures that there is no pressure leakage from the processing area 115.

[0026] A process gas (i.e., an oxidizing medium including an amine additive) is provided to the processing region 115 inside the high pressure vessel 100 by the gas panel 150. The isolation valve 155 is opened by the controller 180 to allow the process gas to flow into the processing region 115 through the inlet conduit 157 and the tube 118. The process gas is introduced at a flow rate of, for example, between about 500 sccm and about 2000 sccm. At this point, the isolation valve 165 remains closed. In some embodiments, the pressure in the high pressure vessel 100 is gradually increased. The high pressure effectively drives the oxygen entering the silicon-containing film into a more fully oxidized state, especially in the deeper portions of the trenches.

[0027] In some embodiments described herein, the process gas is steam including an amine additive at a pressure between about 1 bar and about 65 bar (e.g., between about 35 bar and about 65 bar; or between about 40 bar and 60 bar). However, in other embodiments, other oxidizing media (such as, but not limited to, ozone, oxygen, peroxide, or hydroxide-containing compounds) may be used with or in place of steam. The amine additive added to the oxidizing medium may be ammonium or ammonia. When sufficient steam is released by the gas panel 150, the controller 180 closes the isolation valve 155.

[0028] During the processing of the substrate 135, the processing area 115 and the inlet conduit 157, the outlet conduit 161 and the tube 118 are maintained at a certain temperature and pressure so that the processing gas remains in the gas phase. Under the applied pressure, the temperature of the processing area 115 and the inlet conduit 157, the outlet conduit 161 and the tube 118 is maintained above the condensation point of the processing gas (such as 100 degrees Celsius), but at a temperature of 550 degrees Celsius or below. The processing area 115 and the inlet conduit 157, the outlet conduit 161 and the tube 118 are maintained at a pressure less than the condensation pressure of the processing gas at the applied temperature. The processing gas is selected accordingly. In the embodiment described herein, when the high pressure vessel is maintained at a temperature between about 100 degrees Celsius and about 550 degrees Celsius, steam at a pressure between about 1 bar and about 65 bar is an effective processing gas. This ensures that the steam will not condense into water, which is harmful to the silicon film deposited on the substrate 135.

[0029] As confirmed by testing the wet etch rate and leakage and breakdown characteristics of the film, the process is completed when the film is observed to have the target density. The isolation valve 165 is then opened to allow the process gas to flow from the processing area 115 through the tube 118 and the outlet conduit 161 to the condenser 160. The process gas is condensed into a liquid phase in the condenser 160. The liquefied process gas is then removed by the pump 170. When the liquefied process gas is completely removed, the isolation valve 165 is closed. The power to the heaters 140, 119, 158 and 162 is then turned off. The door 120 of the high pressure vessel 100 is then opened to remove the box 130 from the processing area 115.

[0030] Figure 2A 2 shows a semiconductor device 200 including a substrate 202 and a silicon-containing film 208 deposited on the substrate 202 according to one or more embodiments described herein. Figure 1As shown, when the substrate 202 is loaded onto the cassette 130, the substrate 202 may be used in place of each substrate 135. One or more openings or vias 204 may be formed in the substrate 202. Although only one via 204 is shown in the semiconductor device 200, a plurality of vias 204 may be included. In such an embodiment, each via 204 of the plurality of vias may have the same size, such as having a depth of about 10 μm. In addition, the side 214 and bottom 216 of the via 204 may be patterned and may not be planar as shown. A silicon-containing film 208 may be deposited on each exposed surface (i.e., the top surface 212, the side 214, and the bottom 216) of the substrate 202 and the via 204. Atomic layer deposition (ALD) may be used to deposit the silicon-containing film 208. The silicon-containing film 208 may be composed of silicon or silicon nitride.

[0031] The substrate 202 may contain one or more materials used in forming semiconductor devices, such as metal contacts, trench isolations, gates, bitlines, or any other interconnect features. The substrate 202 may include one or more metal layers, one or more dielectric materials, semiconductor materials, and combinations thereof, for fabricating semiconductor devices. For example, depending on the application, the substrate 202 may include an oxide material, a nitride material, a polysilicon material, or the like. In one embodiment targeting memory applications, the substrate 202 may include a silicon substrate material, an oxide material, and a nitride material, with or without polysilicon sandwiched therebetween.

[0032] In another embodiment, the substrate 202 may include a plurality of alternating oxide and nitride materials (i.e., oxide-nitride-oxide (ONO)) deposited on a surface of the substrate (not shown). In various embodiments, the substrate 202 may include a plurality of alternating oxide and nitride materials, one or more oxide or nitride materials, polycrystalline silicon or amorphous silicon materials, oxides alternating with amorphous silicon, oxides alternating with polycrystalline silicon, undoped silicon alternating with doped silicon, undoped polycrystalline silicon alternating with doped polycrystalline silicon, or undoped amorphous silicon alternating with doped amorphous silicon. The substrate 202 may be any substrate or material surface on which film processing is performed. For example, substrate 202 may be a material such as crystalline silicon, silicon oxide, silicon oxynitride, silicon nitride, strained silicon, silicon germanium, tungsten, titanium nitride, doped or undoped polysilicon, doped or undoped silicon wafers and patterned or unpatterned silicon wafers, silicon on insulator (SOI), carbon-doped silicon oxide, silicon nitride, doped silicon, germanium, gallium arsenide, glass, sapphire, low-k dielectrics, and combinations thereof.

[0033] Figure 2BA semiconductor device 200 having a conformal silicon oxide film 206 formed in a via 204 according to one or more embodiments described herein is shown. The silicon oxide film 206 is formed on a substrate 202 and a silicon-containing film 208 at a temperature of 550 degrees Celsius or less, such as at a temperature of about 350 degrees Celsius to about 505 degrees Celsius. The silicon oxide film 206 is formed using a high pressure anneal at a pressure of 1 bar or more, such as about 35 bar to about 65 bar, in an oxidizing medium including an amine additive.

[0034] The oxidizing medium may include steam, oxygen, peroxide, etc., and the amine additive may include ammonium (NH 4 ) or ammonia (NH 3 The oxidizing medium may include about 1,000 ppm to about 20,000 ppm of an amine additive, such as about 7,000 ppm. In one embodiment, steam is used as the oxidizing medium and about 7,000 ppm of NH 3 As an amine additive. When reacting a film including silicon nitride, a hydrogen-based additive may be added to the oxidizing medium. When reacting a film including silicon nitride, a hydrogen-based additive may be added in addition to the amine additive or as a substitute for the amine additive. The hydrogen-based additive may include pure hydrogen (H 2 ) or trace amounts of hydrogen as a component of the inert gas. Amine and / or hydrogen-based additives added to the oxidizing medium can increase the oxidation rate by about 2 to 3 times compared to high temperature rapid thermal oxidation films. In one embodiment, the annealing process for forming the silicon oxide film 206 is performed at a pressure of about 40 bar to about 60 bar for about one hour.

[0035] The silicon-containing film 208 is disposed between the substrate 202 and the silicon oxide film 206; however, after the silicon oxide film 206 is formed, the silicon-containing film 208 may have a smaller thickness. In one embodiment, the silicon-containing film 208 is completely oxidized so that the silicon-containing film 208 is no longer disposed between the silicon oxide film 206 and the substrate 202 (that is, the silicon oxide film 206 may be in contact with the substrate 202). Although not shown, the silicon oxide film 206 and / or the silicon-containing film 208 may be disposed on the surface 212 of the substrate 202.

[0036] Figure 2C An enlarged cross-sectional view through a top portion of semiconductor device 200 at line 2C-2C is shown. Line 2C-2C may be approximately 500 nm below surface 212 of semiconductor device 200. Figure 2D An enlarged cross-sectional view through a bottom portion of the semiconductor device 200 at the 2D-2D line is shown. The 2D-2D line may be approximately 500 nm above the bottom 216 of the semiconductor device 200. Figure 2C The top portion of the silicon oxide film 206 has a thickness of 210 Å, while Figure 2D The silicon oxide film 206 at the bottom portion has a thickness of 210B (generally referred to as 210).

[0037] like Figure 2C and Figure 2D As shown, the thickness 210A of the top portion of the silicon oxide film 206 is about the same as the thickness 210B of the bottom portion of the silicon oxide film 206. The silicon oxide film 206 has an approximately uniform thickness 210 at both the top portion and the bottom portion of the via 204, indicating about 100% conformality of the silicon oxide layer 206 (i.e., the ratio of the thickness 210A of the top portion to the thickness 210B of the bottom portion). The silicon oxide film 206 formed using an oxidizing medium including an amine additive at a temperature of less than about 550 degrees Celsius and a pressure of greater than 1 bar has a nearly uniform conformality of greater than about 90% on the side 214 and the bottom 216 of the via 204. The silicon oxide film 206 has a uniform thickness 210 of about 20 angstroms to about 400 angstroms, such as about 150 angstroms to about 400 angstroms.

[0038] Figure 3 A process flow diagram of a method 300 for forming a silicon oxide film on a substrate according to one or more embodiments described herein is depicted. The substrate may be Figure 1 The substrate 135 as depicted or as Figures 2A-2D The depicted substrate 202. For clarity, reference will be made to Figures 2A-2D The method 300 is described with reference to the elements of the semiconductor device 200 .

[0039] The method 300 comprises: providing a substrate having a silicon-containing film 208 (eg, Figure 2A The operation 310 begins by loading a substrate 202 (shown in FIG. 1 ) into a high pressure vessel. The high pressure vessel may be Figure 1 The depicted high pressure vessel 100. The substrate 202 may be placed in a box such as Figure 1 130). Before loading the substrate 202 into the high pressure vessel, a silicon-containing film 208 is deposited on each exposed side or surface 212, 214, 216 of the substrate 202 and the via 204. The silicon-containing film 208 may be deposited using ALD. The silicon-containing film 208 may be composed of silicon or silicon nitride. The substrate 202 may be formed from the above Figures 2A-2D Any of the materials discussed in.

[0040] In one embodiment, similar to Figures 2A-2DAs shown in , the surface 212 of the substrate 202 includes a patterned structure, for example, a surface having grooves, holes, or vias 204 formed therein. In such an embodiment, the silicon-containing film 208 is disposed on the sides 214 and the bottom 216 of the vias 204. Alternatively, the surface 212 of the substrate 202 may be substantially flat. The substrate 202 may also have a substantially flat surface 212 having structures formed thereon or therein at a target height. Although the surface 212 of the substrate 202 may include grooves, holes, vias, or elevations, the pattern of the surface 212 will be referred to as vias throughout the specification, and the term "via" is not intended to be limiting.

[0041] At operation 320, the substrate 202 is exposed to an oxidizing medium including an amine additive at a target temperature between the condensation point of the oxidizing medium (e.g., about 100 degrees Celsius) and about 550 degrees Celsius and a pressure greater than 1 bar. In one embodiment, the target temperature is between about 100 degrees Celsius and about 550 degrees Celsius (e.g., between about 350 degrees Celsius and about 520 degrees Celsius; or between about 400 degrees Celsius and about 505 degrees Celsius). Heaters 140a, 140b may be used to raise the temperature to the target temperature. In addition to raising the temperature, the pressure may also be raised to the target pressure. In one embodiment, the pressure is between about 1 bar and about 65 bar (e.g., between about 30 bar and about 65 bar; or between about 40 bar to about 60 bar).

[0042] In one embodiment, the oxidizing medium is selected from the group consisting of steam, ozone, oxygen, water vapor, heavy water, peroxides, hydroxide-containing compounds, oxygen isotopes (14, 15, 16, 17, 18, etc.) and hydrogen isotopes (1, 2, 3) and combinations thereof. The peroxide may be hydrogen peroxide in the gas phase. In some embodiments, the oxidizing medium includes hydroxide ions, such as but not limited to water vapor or heavy water in vapor form. The amine additive may be composed of ammonium or ammonia. The oxidizing medium may include about 1,000 ppm to about 20,000 ppm of the amine additive, such as about 7,000 ppm. In one embodiment, steam is used as the oxidizing medium and about 7,000 ppm of NH 3 As an amine additive. When reacting a film including silicon nitride, a hydrogen-based additive may be added to the oxidizing medium. When reacting a film including silicon nitride, a hydrogen-based additive may be added in addition to the amine additive or as a substitute for the amine additive. The hydrogen-based additive may include pure hydrogen (H 2 ) or trace amounts of hydrogen as a component of the inert gas. Amine and / or hydrogen-based additives added to the oxidizing medium can increase the oxidation rate by about 2 to 3 times compared to high temperature rapid thermal oxidation films.

[0043] In some embodiments, the substrate 202 or multiple substrates are exposed to a steam including an amine additive at a pressure between about 5 bar and about 60 bar, wherein the pressure can be gradually increased from 5 bar to about 60 bar. In some embodiments, the steam including the amine additive is introduced into the high pressure vessel at a flow rate of, for example, between about 500 sccm and about 5,000 sccm (e.g., between about 500 sccm and about 5,000 sccm; or between about 500 sccm and about 2,000 sccm). In one embodiment, water vapor including the amine additive is injected into the high pressure vessel, and when heated in the high pressure vessel, the water vapor forms a steam including the amine additive. In another embodiment, before being heated to the target temperature, water or water vapor including the amine additive will be present in the high pressure vessel. As the high pressure vessel is heated to the target temperature, the water or water vapor present in the high pressure vessel forms a steam including the amine additive.

[0044] At operation 330, a silicon oxide film 206 is formed on the substrate 202. The silicon oxide film 206 is formed as a conformal or uniform layer. The silicon oxide film 206 is uniformly formed on the side 214 and bottom 216 of the via 204 and on the surface 212 of the substrate 202. The silicon oxide film 206 may be deposited to have a conformality greater than about 90% on the side 214 and bottom 216 of the via 204, as shown in FIG. Figures 2A-2D The silicon oxide film 206 may have a thickness 210 of about 20 angstroms to about 400 angstroms, such as about 150 angstroms to about 400 angstroms.

[0045] At operation 330, when the substrate 202 with the silicon-containing film 208 is exposed to an oxidizing medium including an amine additive to form the silicon oxide film 206, the high pressure vessel is maintained at a temperature between the condensation point of the oxidizing medium and about 550 degrees Celsius. In one embodiment using a steam including an amine additive at a pressure of about 40 bar to about 60 bar, the temperature of the high pressure vessel is maintained between about 400 degrees Celsius and about 505 degrees Celsius. In some embodiments, the operation 330 of forming the silicon oxide film 206 on the substrate 202 is performed for a time period between about 5 minutes to about 150 minutes (such as about 30 minutes to about 120 minutes). In at least one embodiment, the silicon-containing film 208 is completely oxidized using an oxidizing medium including an amine additive at a temperature between about 400 degrees Celsius to about 505 degrees Celsius and a pressure of about 60 bar for about 120 minutes, so that the silicon-containing film 208 is no longer disposed between the substrate 202 and the silicon oxide layer 206.

[0046] Applying an oxidizing medium (such as steam including ammonia) including an amine additive under high pressure allows a high concentration of oxidizing species to penetrate deeply into the silicon-containing film from the oxidizing medium, so that the oxidizing species can produce more silicon oxide film material via oxidation. Without being bound by theory, it is believed that the high pressure inside the high pressure vessel drives the oxidizing species to diffuse into deeper vias. In addition, it is believed that the presence of the amine additive in the steam allows the target pressure to be achieved at a faster rate and increases the oxidation rate by 2-3 times compared to high temperature rapid thermal oxidation films.

[0047] The quality of the silicon oxide film 206 can be verified by comparing the wet etching rate of the silicon oxide film 206 formed at a temperature of less than 550 degrees Celsius and a pressure of more than 1 bar using an oxidizing medium including an amine additive with the wet etching rate of the silicon oxide film (i.e., a high temperature rapid thermal oxidation film) formed at a temperature of more than 800 degrees Celsius and at a low pressure without using an amine additive. When both the silicon oxide film 206 having a thickness greater than about 20 angstroms and the high temperature rapid thermal oxidation film having the same thickness are wet etched, the wet etching rate is about the same for the two films. In one embodiment, the silicon oxide film 206 and the high temperature rapid thermal oxidation film both have a wet etching rate of about 26 angstroms / minute to about 32 angstroms / minute.

[0048] In addition, the quality of the silicon oxide film 206 can be further verified by comparing the leakage and capacitance equivalent thickness of the silicon oxide film 206 formed at a temperature below 550 degrees Celsius and a pressure greater than 1 bar using an oxidizing medium including an amine additive with a high temperature rapid thermal oxidation film. When the leakage of the silicon oxide film 206 having a thickness greater than about 20 angstroms is compared with the leakage of the high temperature rapid thermal oxidation film having the same thickness, both silicon oxide films are arranged along the thermal trend line or the extrapolated thermal trend line of the voltage leakage and thickness graph. In this way, the leakage and capacitance equivalent thickness of the silicon oxide film 206 are approximately the same or equivalent to the high temperature rapid thermal oxidation film. In one embodiment, the silicon oxide film 206 and the high temperature rapid thermal oxidation film both have a leakage to capacitance equivalent thickness of about 0.22V / angstrom to about 0.25V / angstrom.

[0049] Thus, for processes performed at relatively low temperatures of 550 degrees Celsius or less, the film quality improvements achieved are substantially similar to processes performed at temperatures of 800 degrees Celsius or more at lower pressures. Processing performed at relatively low temperatures of 550 degrees Celsius or less using an oxidizing medium including an amine additive enables silicon oxide layers to be deposited uniformly, including deposition on substrates having challenging or uneven structures.

[0050] In addition, forming a silicon oxide film using an oxidizing medium including an amine and / or hydrogen-based additive at a temperature of less than 550 degrees Celsius and a pressure of greater than 1 bar enables the silicon oxide film to achieve a thickness greater than the capability of a high temperature rapid thermal oxidation process while maintaining high quality. Thus, depositing a silicon oxide film using an oxidizing medium including an amine additive at a temperature of less than 550 degrees Celsius and a pressure of greater than 1 bar produces a conformal or uniform silicon oxide film having an increased oxidation rate and having the same quality as a high temperature rapid thermal oxidation film.

[0051] Additionally, depositing the silicon oxide film at a temperature of less than about 550 degrees Celsius using an oxidizing medium including an amine additive expands the process window for forming the silicon oxide film as the process window is no longer limited to temperatures of about 800 degrees Celsius or higher. Expanding the process window increases the capabilities of current tools used to form the silicon oxide film, thereby reducing overall resources.

[0052] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope of the disclosure, the scope of which is to be determined by the following claims.

Claims

1. A method for forming a silicon oxide film, comprising the following steps: loading a substrate having a silicon-containing film deposited thereon into a processing region of a high pressure vessel, the silicon-containing film comprising silicon or silicon nitride; and Forming a silicon oxide film on the silicon-containing film comprises the following steps: exposing the silicon-containing membrane to an oxidizing medium comprising an additive comprising ammonium or ammonia at a pressure greater than 1 bar, wherein the oxidizing medium comprises 1,000 ppm to 20,000 ppm of the additive; and The high pressure vessel is maintained at a temperature between 100 degrees Celsius and 550 degrees Celsius.

2. The method of claim 1, wherein the oxidizing medium is selected from the group consisting of steam, peroxide, oxygen, ozone, heavy water, hydroxide-containing compounds, and combinations thereof.

3. The method of claim 1, wherein the silicon-containing film is a silicon nitride film, and wherein the oxidizing medium further comprises a hydrogen-based additive.

4. The method of claim 1, wherein the silicon oxide film has a uniform thickness between 20 angstroms and 400 angstroms, and wherein the temperature is between 400 degrees Celsius and 505 degrees Celsius.

5. The method of claim 1, wherein the step of forming the silicon oxide film on the silicon-containing film is performed for a period of time between 5 minutes and 150 minutes.

6. A method for forming a conformal silicon oxide film, comprising the following steps: depositing a silicon-containing film including silicon or silicon nitride on a substrate including a plurality of vias, the silicon-containing film being deposited on each exposed surface of the substrate and the plurality of vias; loading the substrate having the silicon-containing film deposited thereon into a processing region of a high pressure vessel; and Forming a conformal silicon oxide film on the silicon-containing film comprises the following steps: exposing the silicon-containing film to an oxidizing medium comprising an additive, the additive comprising ammonium or ammonia, wherein the oxidizing medium comprises 1,000 ppm to 20,000 ppm of the additive; and The high pressure vessel is maintained at a temperature between 100 degrees Celsius and 550 degrees Celsius and at a pressure between 1 bar and 65 bar.

7. The method of claim 6, wherein the oxidizing medium comprises 7,000 ppm of the additive.

8. The method of claim 6, wherein the oxidizing medium is selected from the group consisting of steam, peroxide, oxygen, ozone, heavy water, hydroxide-containing compounds, and combinations thereof.

9. The method of claim 6, wherein the oxidizing medium is steam and the additive is ammonia, wherein the silicon-containing film is a silicon nitride film, and wherein the oxidizing medium further comprises a hydrogen-based additive.

10. The method of claim 6, wherein the step of forming the silicon oxide film on the silicon-containing film is performed at a temperature between 400 degrees Celsius and 505 degrees Celsius for a time period between 5 minutes and 150 minutes, and wherein the conformal silicon oxide film has a uniform thickness between 20 angstroms and 400 angstroms.

11. A method for forming a silicon oxide film, comprising the following steps: loading a substrate having a silicon-containing film deposited thereon into a processing region of a high pressure vessel, the silicon-containing film comprising silicon or silicon nitride; and Forming a silicon oxide film on the silicon-containing film comprises the following steps: exposing the silicon-containing film to an oxidizing medium comprising ammonia, wherein the oxidizing medium is selected from the group consisting of steam, oxygen, and peroxides, and wherein the oxidizing medium comprises 1,000 ppm to 20,000 ppm of the ammonia; and The high pressure vessel is maintained at a temperature between 400 degrees Celsius and 505 degrees Celsius and at a pressure greater than 10 bar, wherein the silicon oxide film has a uniform thickness between 100 angstroms and 400 angstroms.

12. The method of claim 11, wherein the pressure is between 10 bar and 60 bar.

13. The method of claim 11, wherein the step of forming the silicon oxide film on the silicon-containing film is performed for a period of 5 minutes to 120 minutes.

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