Method for improving deposition-induced CD imbalance using spatially selective ashing of carbon-based films

Abstract

A method for forming features on a wafer using a carbon-based deposit is provided. The carbon-based deposit is preconditioned, wherein the preconditioning results in non-uniform removal of some of the carbon-based deposit. An oxide deposit of a silicon oxide-based material is deposited by an atomic layer deposition process, wherein the depositing of the oxide deposit results in non-uniform removal of some of the carbon-based deposit that is complementary to the non-uniform removal of some of the carbon-based deposit caused by the preconditioning.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application No. 62 / 591,949, filed on November 29, 2017, and U.S. Application No. 15 / 974,172, filed on May 8, 2018, the entire contents of which are incorporated herein by reference for all purposes.

[0003] background

[0004] The present disclosure relates to the formation of semiconductor devices. More specifically, the present disclosure relates to the formation of semiconductor devices in which pattern multiplication is used to double or quadruple mask density or line frequency. Such pattern multiplication can form oxide spacers around carbon features and then remove the carbon features, thereby allowing the oxide spacers to act as a mask. Summary of the invention

[0005] To achieve the aforementioned objectives and in accordance with the purposes of the present disclosure, a method for forming features on a wafer using a carbon-based deposit is provided. The carbon-based deposit is preconditioned, wherein the preconditioning results in uneven removal of some of the carbon-based deposit. An oxide deposit of a silicon oxide (SiO2) based material is deposited by an atomic layer deposition process, wherein the depositing of the oxide deposit results in uneven removal of some of the carbon-based deposit, which is complementary to the uneven removal of some of the carbon-based deposit caused by the preconditioning.

[0006] In another manifestation, a method for forming a feature on a wafer using a carbon-based deposit is provided. The carbon-based deposit is preconditioned, wherein the preconditioning results in uneven removal of some of the carbon-based deposit. An oxide deposit is deposited by an atomic layer deposition process, wherein the depositing the oxide deposit results in uneven removal of some of the carbon-based deposit. At least one additional process is provided, wherein the at least one additional process completes the formation of a feature on the wafer, wherein the feature is more uniform than a feature that would be formed without the preconditioning.

[0007] These and other features of the present invention will be described in greater detail below in the detailed description of the disclosure and in conjunction with the following figures. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The present disclosure is illustrated by way of example and not limitation in the accompanying figures and in which like reference numerals indicate similar elements and in which:

[0009] Figure 1 is a high-level flow chart of the implementation plan.

[0010] Figure 2is a schematic diagram of a process chamber that may be used in one embodiment.

[0011] Figure 3 is a schematic diagram of a computer system that can be used to practice embodiments.

[0012] Figure 4A -F is a schematic cross-sectional view of a stack processed according to one embodiment.

[0013] Figure 5 is a more detailed flow chart of the preconditioning process.

[0014] Figure 6 is a more detailed flow chart for lower energy oxide deposition.

[0015] Figure 7 is a more detailed flow chart for higher energy oxide deposition.

[0016] Figure 8 is a graph of carbon removal according to one embodiment.

[0017] Fig. 9 is a flow chart of another embodiment. DETAILED DESCRIPTION

[0018] Embodiments of the present disclosure will now be described in detail with reference to several preferred embodiments shown in the accompanying drawings. In the following description, many specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it will be apparent to those skilled in the art that the present disclosure may be implemented without some or all of these specific details. In other cases, well-known process steps and / or structures are not described in detail to avoid making the present disclosure unclear unnecessarily.

[0019] In a common multi-patterning scheme, a carbon-based film is deposited and patterned to define an initial structure. An oxide spacer film is then deposited on the carbon-based film. The oxide spacer film can be etched to expose the carbon-based film, leaving oxide spacers on the sides of the carbon-based film features. The carbon-based film is removed, leaving oxide spacers with a frequency of twice that between features and a spacing and CD of half that between features. If this process is repeated N times, the CD of the final structure will be twice that of the initial structure of the carbon film. -N The deposition and subsequent etching of the oxide spacer film removes some of the carbon film in a non-uniform manner across the wafer. This non-uniform removal of carbon is referred to as loss non-uniformity (NU) across the wafer. In one example, more carbon film was removed within 3 cm of the edge of the wafer compared to the rest of the wafer.

[0020] Conventional techniques rely on tuning the deposition plasma itself to try to minimize the loss NU across the wafer. An obvious problem with this approach is the coupling of the carbon core loss profile and the oxide film thickness profile. If the plasma has already been optimized to minimize the film thickness NU, re-optimization to minimize the loss NU can significantly degrade the performance of the former. This is a classic case of trying to optimize two parameters at once with one knob.

[0021] Another conventional approach may be to adjust the carbon core etch profile across the wafer to compensate for the loss NU imparted by the deposition process. However, etch profile adjustment is generally not easy, and there is generally no willingness to modify a complex etch process to compensate for shortcomings in the deposition process.

[0022] One of the problems with the above scheme is the carbon core loss that can occur during plasma-enhanced ALD oxide deposition. This loss is primarily caused by the oxygen radicals required to grow the oxide film, but can also be caused by heavy ions (such as argon (Ar)) that may also be present in the plasma. This loss is an undesirable consequence of the oxide deposition process and can vary across the wafer. This in turn can make the CD of the final structure vary across the wafer. For example, CD| edge <CD| center Therefore, it is difficult to obtain the target CD everywhere on the wafer without making the deposition plasma very uniform.

[0023] For ease of understanding, Figure 1 1 is a high-level flow chart of an embodiment. A carbon-based deposit is deposited above a wafer (step 104). The carbon-based deposit is preconditioned, wherein the preconditioning causes uneven removal of some of the carbon-based deposit (step 108). An oxide deposit is deposited using a lower energy atomic layer deposition (ALD) process (step 110), wherein the lower energy ALD process does not remove or minimally removes some of the carbon-based deposit. An oxide deposit is deposited using a higher energy ALD process (step 112), wherein depositing the oxide deposit causes uneven removal of some of the carbon-based deposit, which is complementary to uneven removal of some of the carbon-based deposit caused by preconditioning. The oxide deposit is a silicon oxide-based material. The oxide deposit is etched back (step 116). The carbon-based deposit is removed (step 120). An underlying layer is etched, wherein the oxide deposit is used as a mask (step 124).

[0024] Example

[0025] Figure 22 is a schematic diagram of a processing chamber that can be used in one embodiment. In one or more embodiments, the processing chamber 200 includes a gas distribution plate 206 and a wafer support 208 that provide a gas inlet in a chamber 249 surrounded by a chamber wall 252. In the chamber 249, the wafer 203 is positioned above the wafer support 208. The edge ring 209 surrounds the wafer support 208. The gas source 210 is connected to the chamber 249 through the gas distribution plate 206. The support temperature controller 250 is connected to the wafer support 208. A radio frequency (RF) source 230 provides RF power to the upper electrode, which is the gas distribution plate 206 in this embodiment. In an exemplary embodiment, a power supply of 400kHz, 13.56MHz and optionally 2MHz, 27MHz constitutes the RF source 230. In this embodiment, the wafer support 208 is grounded. In this embodiment, a generator is provided for each frequency. In other embodiments, the generator can be in a separate RF source, or a separate RF generator can be connected to different electrodes. For example, the upper electrode may have inner and outer electrodes connected to different RF sources. Other arrangements of RF sources and electrodes may be used in other embodiments. Controller 235 is controllably connected to RF source 230, exhaust pump 220, and gas source 210. An example of such an etching chamber is the Striker 200 manufactured by Lam Research Corporation (Fremont, CA). TM Oxide system.

[0026] Figure 3 300 is a high-level block diagram showing a computer system 300 suitable for implementing the control circuit 235 for the embodiment. The computer system can have a variety of physical forms, ranging from integrated circuits, printed circuit boards, and small handheld devices to giant supercomputers. The computer system 300 includes one or more processors 302, and may also include an electronic display device 304 (for displaying graphics, text, and other data), a main memory 306 (e.g., random access memory (RAM)), a storage device 308 (e.g., a hard drive), a removable storage device 310 (e.g., an optical drive), a user interface device 312 (e.g., a keyboard, a touch screen, a keypad, a mouse, or other positioning devices, etc.) and a communication interface 314 (e.g., a wireless network interface). The communication interface 314 enables software and data to be transmitted between the computer system 300 and external devices through a link. The system may also include a communication infrastructure 316 (e.g., a communication bus, a cross-over bar, or a network), and the aforementioned devices / modules are connected to the communication infrastructure 316.

[0027] The information transmitted via the communication interface 314 may be in the form of a signal that can be received by the communication interface 314 through a communication link, such as an electronic, electromagnetic, optical, or other signal, which carries the signal and can be a communication link implemented using wires or cables, optical fibers, telephone lines, cellular phone links, radio frequency links, and / or other communication channels. Using such a communication interface, it is expected that one or more processors 302 can receive information from a network or can output information to a network during the implementation of the above-mentioned method steps. In addition, the method implementation can be executed only on the processor or can be executed in conjunction with a remote processor on a network such as the Internet, and the remote processor shares a portion of the processing.

[0028] The term "non-transitory computer-readable medium" is generally used to refer to media such as main memory, auxiliary memory, removable storage, and storage devices (such as hard disks, flash memory, hard drive memory, CD-ROMs, and other forms of permanent memory), and should not be interpreted as covering transient subject matter such as carrier waves or signals. Examples of computer code include machine code, such as produced by a compiler, and files including higher-level code executed by a computer using an interpreter. The computer-readable medium may also be computer code transmitted by a computer data signal embodied in a carrier wave and represented as a sequence of instructions executable by a processor.

[0029] In an example of an implementation of an embodiment, a carbon-based deposit is formed over a wafer (step 104 ). Figure 4A is a schematic cross-sectional view of a portion of a stack 400, wherein a wafer 404 is disposed below an intermediate layer 408, which is disposed below a carbon-based deposit 412. In this example, the carbon-based deposit 412 is an organic patterned mask, such as a photoresist mask, having a first mask feature 414 and a second mask feature 416. One or more layers (not shown) may be disposed between the wafer 404 and the intermediate layer 408. One or more layers (not shown), such as an anti-reflective coating, may also be disposed between the intermediate layer 408 and the carbon-based deposit 412.

[0030] The carbon-based deposits are pre-conditioned, wherein the pre-conditioning results in uneven removal of some of the carbon-based deposits. Figure 5is a more detailed flow chart of the preconditioning step. A preconditioning gas is provided and flows into the process chamber (step 504). In this example, the preconditioning gas is 1000 sccm O2, 1500 sccm Ar, and 25,000 sccm N2. The preconditioning gas is converted into a plasma (step 508). In this example, 750 watts of RF is provided at a frequency of 13.56 MHz. A bias voltage of 15 volts is provided. After 3 seconds, the flow of the preconditioning gas into the process chamber is stopped (step 512). Figure 4B is a cross-sectional view of stack 400 after carbon-based deposits 412 have been pre-conditioned (step 108). Typically, NUs are across wafer 404, where the center of wafer 404 may not be processed uniformly relative to features at the edge of the wafer. Figure 4B The non-uniformity in the features shown side by side is schematically shown, where such non-uniformity is actually in the spaced apart features. In addition, certain aspects have been exaggerated to illustrate general aspects of the embodiments. In this example, some first mask features 414 are removed by preconditioning, and second mask features 416 are not removed by preconditioning.

[0031] A lower energy oxide deposit is deposited on the carbon-based deposit by an ALD process (step 110 ). Figure 6 6 is a more detailed flow chart of a lower energy oxide deposition (step 110). A precursor gas is flowed into the process chamber (step 604). In this example, the precursor gas is 400 sccm of aminosilane. After 0.4 seconds, the flow of the precursor gas into the process chamber is stopped (step 612). A silicon-containing precursor layer is deposited on the carbon-based deposit 412. A first purge gas is flowed into the process chamber (step 616). In this example, the first purge gas is argon and oxygen (O2). The flow of the first purge gas is stopped (step 620). An oxidizing gas is flowed into the process chamber (step 624). In this example, the oxidizing gas is 13,000 sccm Ar and 1500 sccm O2. The oxidizing gas is converted into a plasma (step 628). In this example, 100 to 500 watts of RF is provided at a frequency of 13.56 MHz. After 0.25 seconds, the flow of the oxidizing gas into the process chamber is stopped (step 632). The plasma from the oxidizing gas converts the deposited silicon-containing precursor layer into silicon oxide. A second purge gas is flowed into the process chamber (step 636). The flow of the second purge gas is stopped (step 640). The cycle is then repeated starting with the step of flowing the precursor gas into the process chamber (step 604). In this example, the process is repeated for 2 to 10 cycles. A lower energy oxide deposition (step 110) is performed at a sufficiently low energy to deposit a silicon oxide layer while minimizing damage to the carbon-based deposit 412.

[0032] A higher energy oxide deposit is deposited on the carbon-based deposit by an ALD process (step 112 ). Figure 7 is a more detailed flow chart of the higher energy oxide deposition (step 112). A precursor gas is flowed into the processing chamber (step 704). In this example, the precursor gas is 400 sccm of aminosilane. After 0.25 seconds, the flow of the precursor gas into the processing chamber is stopped (step 712). A silicon-containing precursor layer is deposited on the carbon-based deposit 412. A first purge gas is flowed into the processing chamber (step 716). In this example, the first purge gas is argon and oxygen. The flow of the first purge gas is stopped (step 720). An oxidizing gas is flowed into the processing chamber (step 724). In this example, the oxidizing gas is 13,000 sccm Ar and 1500 sccm O2. The oxidizing gas is converted into a plasma (step 728). In this example, 800 to 1200 watts of RF are provided at a frequency of 13.56 MHz. In this example, the RF power provided during the higher energy oxide deposition is higher than the RF power provided during the lower energy oxide deposition. More preferably, the RF power provided during the higher energy oxide deposition is at least 300 watts higher than the RF power provided during the lower energy oxide deposition. In some embodiments, the RF power provided during the higher energy oxide deposition is at least twice the RF power provided during the lower energy oxide deposition. After 0.4 seconds, stop the flow of the oxidizing gas into the processing chamber (step 732). The plasma from the oxidizing gas converts the deposited silicon-containing precursor layer into silicon oxide. Make the second purge gas flow into the processing chamber (step 736). Stop the flow of the second purge gas (step 740). Then repeat the cycle (step 704) from the step of making the precursor gas flow into the processing chamber. In this example, the process repeats 126 to 134 cycles. Due to the protective film formed during the previous lower energy oxide deposition, the higher energy oxide deposition (step 112) is less damaging to the carbon-based deposit 412.

[0033] Figure 4C4 is a cross-sectional view of stack 400 after a higher energy oxide deposit is deposited on carbon-based deposit 412 (step 112). In this example, oxide deposit 420 has unevenly removed carbon-based deposit 412 by removing more second mask features 416 than first mask features 414. The uneven removal of carbon-based deposits by depositing oxide deposit 420 is complementary to the uneven removal of some of the carbon-based deposits by preconditioning because the combination of the uneven removal of some of the carbon-based deposits by depositing oxide deposits and the uneven removal of some of the carbon-based deposits by preconditioning results in more uniform removal of carbon-based deposits than the uneven removal of some of the carbon-based deposits by depositing oxide deposits alone. In this example, the amount removed from first mask feature 414 is approximately equal to the amount removed from second mask feature 416.

[0034] In this example, a separate step is used to etch back the oxide deposit 420 (step 116) to expose a portion of the carbon-based deposit 412. An example recipe for etching back the oxide deposit 420 is a reactive ion etch (RIE) with a fluorine-containing species. Figure 4D is a cross-sectional view of the stack 400 after the oxide deposit 420 has been etched back.

[0035] The carbon-based deposits are removed (step 120). One example of a recipe is plasma ashing with an oxygen-containing species. Figure 4E is a cross-sectional view of stack 400 after carbon-based deposits have been removed.

[0036] The underlying layer is etched, using the oxide deposit as a mask (step 124). In this example, the underlying layer being etched is the intermediate layer 408, which in this example is polysilicon. Figure 4F is a cross-sectional view of the stack 400 after etching the intermediate layer 408 .

[0037] Figure 8 It is shown how the final carbon-based deposit removal profile can be flattened by superimposing the loss profiles of the pre-conditioning and deposited oxide deposits. Figure 8 A graph of carbon removal due to preconditioning versus distance from the center of the wafer is shown 804. A graph of carbon removal due to higher energy oxide deposition versus distance from the center of the wafer is also shown 808. The sum of carbon removed by preconditioning and high energy oxide deposition is also plotted 812. The sum of carbon removed by both preconditioning and higher energy oxide deposition 812 is equivalent to performing these two processes sequentially.

[0038] Table 1

[0039]

[0040] Table 1 shows the average loss in angstroms and loss range for carbon-based deposits resulting from higher energy oxide deposition alone and from the sum of preconditioning and higher energy oxide deposition in one example. In this example, the bowl-shaped loss profile of the higher energy oxide deposition process is compensated by the dome-shaped profile of the preconditioning. The final profile is much flatter than that of higher energy oxide deposition alone, with the loss range observed to be from 1.34 to 2.13 mm / s. The improvement is equal to the sum of the losses due to preconditioning and higher energy oxide deposition. In this example, the lower range indicates improved uniformity. By properly trimming the preconditioning using the available process knobs (adjustment inputs), the removal of carbon-based deposits from the preconditioning can be minimized. Preferably, less than More preferably, the carbon-based deposits less than Preferably, the removal or loss of carbon-based deposits by preconditioning and higher energy oxide deposition is less than More preferably, the removal or loss of carbon-based deposits by preconditioning and higher energy oxide deposition is less than In various embodiments, a target removal depth is provided because the target removal depth is used to determine a complex manufacturing process. Providing a process that makes the thickness of the removed carbon significantly greater than or less than the target removal depth will change the complex manufacturing process in a way that reduces the yield. In some embodiments, pre-conditioning is provided to increase the thickness of the removed carbon. If only standard higher energy oxide deposition is used, the carbon removed will be greater than the target thickness. Providing a lower energy oxide deposition reduces the thickness of the removed carbon. By providing a combination of lower energy oxide deposition and higher energy oxide deposition, the target removal depth is achieved.

[0041] The above embodiments provide a more uniform pattern by providing preconditioning with complementary removal of non-uniform carbon-based deposits relative to the non-uniform removal of carbon-based deposits caused by oxide deposition. This improvement increases uniformity and reduces defects as device dimensions shrink.

[0042] In various embodiments, preconditioning can be completed in situ before the oxide deposit is about to be deposited. In various embodiments, the carbon-based deposits accumulated after preconditioning and depositing the oxide deposits are removed substantially uniformly or otherwise trimmed to meet a given integration requirement. In one embodiment, the removal of the carbon-based deposits by preconditioning is minimized by biasing the etching profile to the extent that the removal caused by the deposited oxide deposit is minimal. In various embodiments, preconditioning can use a preconditioning gas comprising at least one of oxygen, nitrogen or argon. Preconditioning enables the etching profile to be adjusted, and the etching profile can be modulated and trimmed by changing the corresponding ratio of the gas components. In addition, the pressure and RF power of the preconditioning can also be used to further adjust the etching profile.

[0043] In various embodiments, both feed-forward and feedback schemes can be used as part of the process implementation. For the feed-forward scheme, the inspection results after the previous etch step can be used as input to the controller to determine the best settings for preconditioning. For the feedback scheme, the final CD measurement after oxide deposition and etching can be used as input.

[0044] Various embodiments provide independent controllability of carbon deposit removal. Plasma preconditioning has no other function except preconditioning the loss profile, thereby providing flexibility in terms of the profiles (e.g., bowl, dome, and planar) that can be achieved. In some embodiments, preconditioning is performed in situ in the same module as oxide deposition, and no additional hardware or facilities are required. For a typical desired profile, preconditioning increases the total deposition time by less than ten seconds, thereby minimizing any time impact. The relative flow ratios and relative flow rates of different gases (e.g., Ar, N2, and O2) used for preconditioning gases are used as control parameters to adjust the uneven preconditioning of carbon-based deposition.

[0045] Fig. 9904. The carbon-based deposit is deposited above the wafer. The carbon-based deposit is preconditioned, wherein the preconditioning results in uneven removal of some of the carbon-based deposit (step 908). An oxide deposit is deposited by an ALD process (step 912), wherein the deposited oxide deposit results in uneven removal of some of the carbon-based deposit. The oxide deposition is a silicon oxide-based deposition. At least one additional process is provided (step 916), wherein the at least one additional process completes the formation of features above the wafer, wherein the features are more uniform than the features that would be formed without preconditioning. For different processing chambers, the processing chamber may provide an uneven process for the at least one additional process. In this case, instead of a uniform flat profile after depositing silicon oxide, after depositing the oxide deposit, a trimmed profile is required to compensate for the unevenness of the at least one additional process, because the processing chamber will use the trimmed profile to provide a more uniform semiconductor across the wafer after the at least one additional process. Preconditioning is designed to provide a trimmed profile after deposition of the oxide deposit so that the resulting features are more uniform than without preconditioning.

[0046] In various embodiments, oxygen in the preconditioning gas provides some ashing to cause some carbon-based deposit removal during preconditioning. Argon and nitrogen in the preconditioning gas can be used for uniformity control, where the ratio of oxygen to argon to nitrogen can be used to adjust the profile of carbon-based deposits. In some embodiments, the ratio of oxygen to argon for the preconditioning gas is between 2:1 and 1:2.

[0047] In various embodiments, the carbon-based deposit 412 can be amorphous carbon, photoresist, spin-on carbon, or chemical vapor deposited (CVD) carbon or an ashable hard mask.

[0048] Although the present disclosure has been described according to several preferred embodiments, there are changes, modifications, permutations and various alternative equivalents that fall within the scope of the present invention. It should also be noted that there are many alternatives to the methods and devices of the present disclosure. Therefore, the following appended claims are intended to be interpreted as including all such changes, modifications, permutations and various alternative equivalents that fall within the true spirit and scope of the present invention.

Claims

1. A method for forming features on a wafer using a carbon-based deposit, comprising: preconditioning the carbon-based deposits, wherein the preconditioning results in uneven removal of some of the carbon-based deposits; and An oxide deposit of a silicon oxide-based material is deposited by an atomic layer deposition process, wherein said depositing of said oxide deposit results in a non-uniform removal of other ones of said carbon-based deposits that is complementary to the non-uniform removal of some of said carbon-based deposits caused by said preconditioning.

2. The method of claim 1 , wherein the uneven removal of the other ones of the carbon-based deposits caused by the oxide deposits is complementary to the uneven removal of the some of the carbon-based deposits caused by the preconditioning, in that the combination of the uneven removal of the other ones of the carbon-based deposits caused by the depositing of the oxide deposits and the uneven removal of the some of the carbon-based deposits caused by the preconditioning results in more uniform removal of the carbon-based deposits than the uneven removal of the other ones of the carbon-based deposits caused by the depositing of the oxide deposits.

3. The method according to claim 2, wherein: The more uniform removal is more uniform removal across the entire wafer.

4. The method according to claim 1, further comprising: removing the carbon-based deposits; as well as Using the oxide deposit as a mask, the etch layer below the oxide deposit is etched.

5. The method according to claim 1, wherein: The preconditioning of the carbon-based deposit comprises: providing a pre-conditioned gas comprising at least one of Ar or nitrogen and oxygen, converting the preconditioned gas into a plasma, which results in non-uniform removal of some of the carbon-based deposits; and The pre-conditioned gas is stopped.

6. The method according to claim 5, wherein: The pre-regulated gas includes oxygen and argon, wherein the flow ratio of the oxygen to the argon is between 2:1 and 1:

2.

7. The method according to claim 1, wherein: The preconditioning removes less than thickness of the carbon-based deposit.

8. The method according to claim 7, wherein: The depositing of the oxide deposit and the preconditioning provide less than about 1% of the carbon-based deposit across the wafer. removal range.

9. The method according to claim 1, wherein: The preconditioning removes the carbon-based deposits with a dome-shaped profile, and wherein the depositing the oxide deposits removes the carbon-based deposits with a bowl-shaped profile.

10. The method according to claim 1, wherein: The depositing the oxide deposit comprises: A plurality of cycles of lower energy oxide deposition are provided, wherein each cycle comprises: flowing a precursor gas; flowing an oxidizing gas; providing a first RF power to convert the oxidizing gas into plasma; and A plurality of cycles of higher energy oxide deposition are provided, wherein each cycle comprises: flowing a precursor gas; flowing an oxidizing gas; and A second RF power is provided to convert the oxidizing gas into plasma, wherein the second RF power is higher than the first RF power.

11. The method of claim 1 , further comprising providing at least one of a feedback input or a feedforward input to optimize the preconditioning.

12. A method for forming features on a wafer using carbon-based deposits, comprising: preconditioning the carbon-based deposits, wherein the preconditioning results in uneven removal of some of the carbon-based deposits; depositing an oxide deposit by an atomic layer deposition process, wherein said depositing said oxide deposit results in non-uniform removal of other ones of said carbon-based deposits; and At least one additional process is provided, wherein the at least one additional process completes the formation of features on the wafer, wherein the features are more uniform than features that would be formed without preconditioning.

13. The method according to claim 12, wherein: The features are more uniform across the wafer.

14. The method according to claim 12, further comprising: removing the carbon-based deposits; as well as Using the oxide deposit as a mask, the etch layer below the oxide deposit is etched.

15. The method according to claim 12, wherein: The preconditioning of the carbon-based deposit comprises: providing a pre-conditioned gas comprising at least one of Ar or nitrogen and oxygen, converting the preconditioned gas into a plasma, which results in non-uniform removal of some of the carbon-based deposits; and The pre-conditioned gas is stopped.

16. The method according to claim 15, wherein: The pre-regulated gas includes oxygen and argon, wherein the flow ratio of the oxygen to the argon is between 2:1 and 1:

2.

17. The method according to claim 12, wherein: The preconditioning removes less than thickness of the carbon-based deposit.

18. The method according to claim 12, wherein: The depositing the oxide deposit comprises: A plurality of cycles of lower energy oxide deposition are provided, wherein each cycle comprises: flowing a precursor gas; flowing an oxidizing gas; providing a first RF power to convert the oxidizing gas into a plasma; and providing a plurality of cycles of higher energy oxide deposition, wherein each cycle comprises: flowing a precursor gas; flowing an oxidizing gas; and A second RF power is provided to convert the oxidizing gas into plasma, wherein the second RF power is higher than the first RF power.

19. The method of claim 12, further comprising providing at least one of a feedback input or a feedforward input to optimize the preconditioning.

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