TWI305664B - Sidewall smoothing in high aspect ratio/deep etching using a discrete gas switching method - Google Patents

Description

1305664 发明, invention description: [Related application reference] This application is published in the US Provisional Patent Application No. 60/403, 891, the application date is August 16, 2002, and the name is used by Ming Cong, nickname The high aspect ratio/deep etch sidewall smoothing of the discontinuous gas switching method claims priority and is related thereto, and the contents of this provisional patent application are hereby incorporated by reference. FIELD OF THE INVENTION The present invention relates generally to the field of semiconductor fabrication, and more particularly to a preferred embodiment of the invention for improving time-division multiplex deposition/etching processes using adjustable fast discontinuous gas switching. Gas is alternately delivered to the deposition/etching chamber and bypasses the chamber. BACKGROUND OF THE INVENTION The manufacture of microelectromechanical systems (MEMS) components, Α^, and yttrium are widely used in the aspect ratio of the aspect ratio, which is the depth of a hundred meters. In order to ensure the number of gas, the etching process must be known under high etching speed to maintain the proper ^ At ^. To ensure proper component b, the sidewall smoothness is usually X critical conditions. [Prior Art] The traditional single-step electric erosion m _ . The 丨 丨 process cannot meet the inflammation of the peptide at the same time, thus developing a time-sharing system. Inscribed ο α -V Ri ^ 裎 裎 构成 构成 构成 构成 构成 构成 构成 构成 构成 构成 构成 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 , No. 893 is also known, Bosch (B (10); ° i TDM I insect engraving process in a structure with high-density electric polymerization source, typically induced plasma (icp) source, and radio frequency (10) dust substrate electrode The process gas most commonly used in the ruthenium etching process is typically hexafluoride (sFe) as the (iv) gas and octafluorobutane (c4F8) as the deposition gas. In the rhyme step, SF6 is beneficial. Spontaneous Shixi isotropic (IV), and in the deposition step, it is beneficial to deposit the polymeric layer of the aquifer on the sidewall and bottom of the sculpt structure. TM rhyme/deposition alternate process or, Bosch, process cycle Ground alternation (four) and deposition process step width to width ratio structure is defined in the mask Due to the abundant energy and directional ions in the etching step (4), the previous deposition step covers the polymerization at the bottom of the (4) structure, which will be removed, and the germanium substrate is exposed, and further etching is performed. The polymeric film will still be present because it is not subject to direct ion bombardment, thereby inhibiting lateral etching. Although the TDM process consists of multiple etch-deposit cycles, any etching or deposition (or both) of this cycle The part can be further divided into multi-step sections. By the TDM method, the high aspect ratio feature pattern can be defined in the germanium substrate with a high S i etch rate. Conventionally, in the process of the traditional TDM (four) process , f must be adjusted (process transformation of conventional techniques) to maintain vertical feature contours, especially higher aspect ratios. Bhardwaj et al. (US Patent 6 〇 515 〇 3) and others (US Patent 6, 284) '148' indicates that increasing the deposition rate and/or reducing the etch rate at the beginning of the process is a solution to this problem. Bhardwa j points out that the process between cycles and cycles in the TDM process can be changed 1305664 The gas/IL finalizes the adjustment of the deposition/etch rate. The traditional TDM surrogate device uses a combination of multiple mass flow controllers (MFC) and isolation valves to control the gas input process chamber, in the etch zone, SFs '' Opening the body (t, SFe to the process chamber) is often advantageous (but not essential) to discharge the deposition gas (cj8) out of the process chamber. Similarly, in the deposition step, ''open (supply to the process chamber) It is often advantageous (but not essential) to vent the etching gas (SFe) out of the process chamber. It is known that opening the MFc at the beginning of the process step will produce a short pressure "flush" into the chamber until the MFC stabilizes to the set value. For processes with longer step times, the effect of 'punching dust' on the process is irrelevant. However, 'when the manufacturing step time is shortened, the 'rush,' pressure will make the process pressure uncontrolled during a significant portion of the section process time. For TDM etching, $, when the zone time is in each zone At 5 seconds, these repetitive pressure flushes can adversely affect process reproducibility and stability. This is also known in the "off," state to maintain MFC at a slightly lower set point (close to / seem ), rather than zero flow, improves stability. However, there is still a need for a gas control system to facilitate stable system operation in processes that require rapid re-adjustment of gas composition changes. One limitation of the TDM method for etching is the formation of rough feature sidewalls that are caused by the periodic etch/deposition system used in the 5TDM etch process and are "sectorized" to the side walls of the prior art. For the application of MEMS components, the sidewalls need to be roughened or fanned. The degree of fanning in the TDM etching process is usually measured by the fan length = depth, and the fan length is the distance between the peak and the peak of the rough sidewall. Gudan 1305664

The connection is related to the depth of the surname reached during the single-touch cycle. The distance between the large peak of the rough side j and the low recess is directly related to the degree of asymmetry of the single-etching; By shortening the duration of each (four) / (short sculpt / deposition cycle, and repeating at high frequency "to minimize the degree of fan formation, or to make each surname step: more non-equal Directional (for example, in the (four) agent with a small amount of purification in the etching step)

In addition to the smoother feature sidewalls, a higher double (four) rate is also required, and the overall (four) rate of the simple (four) process can be increased by increasing the time spent by the loop, or by increasing each of the (four) loops two: Both, these two methods will lead to a larger fan shape and the final: the formation of the wall. In the conventional and engraving process, a faster recording rate can be achieved only for the (four) thicker sidewalls. Therefore, a TDM meal process with a higher rate is required for the sidewall of the sliding feature. 'Y y η et al. published in 1999 without a support message, claiming that "generally" higher power versus willpower ratio and shorter button cycle tend to

To alleviate this (fan) effect, we can easily understand that at a given power-destroy power level, the lower SFe will have a lower characterization rate, and the lower c4F8 will get More polymer deposition, which leads to a lower (four) rate of the car's father. Although AyQn recommends a lower cycle time, the description results only explore the process of deposition cycle time of 6 seconds or more and ^ seconds or more _ cycle time. Scope, but not exposed to faster time scales to control process gas. In the traditional TM surname reactor, even when the gas MFCs are "off, 10 1305664 state Bf is set to a low set value, its other" The time back to the practical process section of fc is 2 seconds. Therefore, (10) enables faster gas switching to achieve shorter process section times. There are a number of teams that have been published using the (4) method for deep (four) results. 'These processes published by these teams are all 〆 * 〇 ^ ^ ^ ^ ^ longer sedimentary 曰 曰 1 ' and its publication (four) engraved time is 1G seconds Or longer. The person proposes to use a fast (four) flow controller to obtain a shorter cycle time:::: propose a deposition cycle of the clock, and 5 seconds of money to recruit BI_ not disclosed in the deposition and money engraving of the process The paragraph has passed. The gas flow switching method that allows the mass flow controller to maintain (4) the deposited gas in a near-flowing manner. It is also customary to replace the isotropic buttoning step with an anisotropic step to minimize the degree of fanning in the deep stone. For example, the addition of oxygen (〇2) or nitrogen (N2) to the % emulsion during the silver engraving cycle slows the button engraving rate of the sidewalls (lateral engraving rate). This reduced lateral direction (four) is due to the formation of dioxins or nitrides on the walls. The = method reduces fanning, but it sacrifices the overall feature rim. Note that the resulting oxide or nitride protective layer is typically only a few single layers thick, which makes the process more difficult to control. US Patent 6'3〇3, 5l2 (Laermer et al.) emphasizes this limitation by using an alternating system based on SiF4/〇2: chemistry. One of the disadvantages of this technique is the need to add a clear = oxygen gas (such as CHF3, Cf4, etc.) to the plasma to minimize the oxide formed on the etched front σ卩 to achieve the desired overall The etch rate 6 ' 3 0 3, 512 patent does not disclose a TDM cycle of 1356664 ring time of less than 5 seconds per segment or use a process gas bypass line to help make the process section cycle time less than 5 seconds. The time-division multiplexed engraving patent (U.S. Patent 5,501,893, Laermer et al.) discloses gas switching, and the 5,5,1,893 patent states that gas switching is performed for each process section in a length of approximately one minute. However, it does not propose the use of a gas bypass g-line for pumping, and a shut-off valve as a tool for rapidly switching process gases between the etching and deposition steps.

Suzuki et al. also disclose a gas switching method for TDM processes (US Patent 4, 579, 623) 'Suzuki proposes to use a shut-off valve and a needle valve to perform a gas pulse in spring to maintain a fixed gas flow, and the shut-off valve can convert gas gas. The human I cavity is either discharged or discharged to prevent pressure between the needle and the chamber. Due to the use of needle valves for gas switching, the technology disclosed by Suzuki is limited to fixed gas flow processes and does not allow for "conversion". For example, Chan does not disclose gases that can be used to change the gas flow in the process of (10). Switch. '

S-read ki also proposes to discharge gas between the needle valve and the shut-off valve during the period when the gas is not input into the vacuum chamber (the "off" cycle of the gas not input process), which prevents pressure between the needle and the shut-off valve. Suzuki did not propose to circulate the gas to the same chamber downstream of the reaction zone to supply the system with a more uniform gas when the process gas cycle time exceeded the time. In addition, although Suzuld proposed a gas-repellent and repetitive plasma surface treatment process with gas switching, Suzuki did not propose a gas switching to perform a TDM process consisting of alternating etching and polymerization steps. 6 61) Revealed via use

Heinecke et al. (U.S. Patent 4, 935 12 1305664 shut-off valves and mass flow controllers (MFCs) gas pulses, He-Team proposes to use a shut-off valve to pulse the process gas after the IU is in the form of a milk body @ MFX. Heinecke did not provide a “close” (four) path for the process gas bypass. Heinecke suggested that mfc should be “opened” when the shut-off valve is in the “off” position to create pressure between the MFC and the valve line. So __ come, The #valve is opened for the next process to recycle the gas, and the "rushing" pressure of the gas is released to the process chamber. Heinecke does not propose to use the bypass path to make the process gas "off" I state (not input) Process chamber) 'MFC still maintains "open" without creating dust in the pipeline.

Heinecke did not propose the use of gas pulses in the cyclic etch/deposition process.

Bhardwa et al. (U.S. Patent 6, 〇 515 〇 3) propose to use a gas switching to perform a gas-to-cycle or cycle-to-cycle gas-to-cycle process. Bhardwaj did not propose pumping with a gas bypass line and using a shut-off valve as a tool to quickly switch process gases between etching and deposition steps.

Van Suchtelen et al. (u s. patent 4 916 〇 89) proposes to pulse a gas for epitaxial deposition. Van Suchtelen, while proposing the use of a mass flow controller and a gas bypass line to switch gases, did not suggest the use of gas pulses for the etching process, the plasma process, or the cyclic etch/deposition process. SUMMARY OF THE INVENTION Overview of the Invention 13 1305664 One preferred embodiment of the present invention refers to a device for providing gas to a chamber for deposition and etching processes. The apparatus includes an etching gas: an associated gas inlet for providing an etching gas to the chamber and an associated gas outlet downstream of the reaction zone in the same vacuum system to discharge the etching gas; having an associated gas a deposition gas supply at the inlet, providing a deposition gas to the chamber, and - an associated gas exiting the deposition gas, downstream of the reaction zone in the same vacuum system; and: a gas control switcher's (four) engraved gas supply and The deposition gas supply 'makes the gas population and the gas discharge f structure as # when the gas population is closed, the gas can flow out from the gas discharge pipe. The gas control switch controls the flow of the etched gas and the deposited gas from its associated gas population to the chamber so that when the gas begins to flow into the chamber, no pressure pulses are generated. Therefore, the flow of gas from the gas inlet to the chamber allows the gas to flow into the chamber at a substantially constant pressure. In a specific example of the 鲛 夕 夕 鹏 鹏 , , , , , , , , , , 乳 乳 乳 乳 乳 乳 乳 乳 乳 乳 乳 乳 乳 乳 乳 乳 乳 乳 乳

Another preferred embodiment of the present invention is directed to a gas supply system for supplying a gas to a deposition/etching chamber for manufacturing semiconductor wafers, dry bodies, etc., the gas supply/system comprising a mass flow controller for ^ ^ used to supply gas flow; a gas into t, the gas of the mass flow controller is introduced into the 灶 ★ stove "Zhao Li introduced 5 Hai deposition / etching chamber; one gas is bypass" when the gas inlet is closed 昧When the pull is closed, the gas from the mass flow controller is received. 'This gas can be an etching gas or a sinking sea. Xu ^ a, a brother bar, and a discontinuous gas switch, control from the mass flow control stay #规 * - - 制 制 矾 矾 , , , , , , , , ,

The gas flow of the controller can be alternately pulsed between the gas π hopper a A milk inlet and the gas bypass. 14 1305664 Another preferred and <1*lu y ” touch ώ L 〃 body example of the present invention refers to controlling the flow of the rolled body from the mass flow controller to the semiconductor manufacturing chamber 丨丨 .. In order to maximize the smoothness of the sidewall of the etched trench on the ruthenium substrate, the reference to the M > A, ,, and Fengfang, the gas flow of the Benbegu 疋 is provided by the mass flow controller, when the gas 鞒# 田孔体When in working state, the gas flow from the mass flow controller is supplied to the chamber, and when the winter solstice milk body is in a stopped state, the gas flow output from the mass flow controller to the sputum preparation chamber is turned to the mass flow, so that the mass flow The gas pressure for controlling the stolen supply is maintained at a relative constant value. Another comparative JL _杳·七丨γ of the present invention

The example refers to the method of a chamber anisotropic electro-hydraulic engraving, in order to form a groove structure with a side-by-side definition, and the inner crucible has smooth sidewalls. Shen Zhaotai, ',, the party goes, provides a reactive etching gas pulse to the chamber to etch the ruthenium while the body is pulsed to deposit a living room. ', "/ aerated shirt, a δ layer. The reactive etching gas and the reactive polymerization gas are output by the mass flow controller at a rate that is substantially fixed, φ, and Anshan. At least one etching step with the reactive Yu Xuan, . Etching to the contact of the rolling body, etching the surface of the crucible with plasma

And removing the material from the surface of the crucible to form an exposed surface. Contacting the reactive polymerization gas in at least one polymerization step to polymerize at least one polymer to the surface of the stone, while covering the surface exposed by the previous (four) step with a polymerization layer - thus forming a temporary (four) Lieutenant, and alternately repeat the rhyming step and the aggregation step. Preferably, the reactivity of the gas and the polymerization gas during the disordered pulse working state and the gas pulse stop working state are: the texture is maintained, which can provide a gas bypass to achieve when the reactive gas stops generating pulses. At this time, the reactive gas is allowed to bypass the reaction zone of the chamber. The above specific examples of the present invention provide several prior art improvements. By 15 1305664, the etching of the wheel-in process chamber and the variation of the pressure of the deposition gas are minimized, and the specific example of the present invention can reduce the characteristic pattern of the engraved stone substrate. A fan shape is formed on the side. In addition, reducing the input pressure pulse can greatly shorten the process cycle time of the surname/deposition replacement process, and shortening the process time can increase the production cycle of the f process, thereby reducing the cost of the final product. Therefore, the present invention is an improvement over the prior art. Detailed description of the invention

A preferred embodiment of the present invention refers to a device for improving the time division multiplex etching process using an adjustable fast discontinuous gas bone switching input process gas, which can improve sidewall smoothness through fanning reduction while maintaining s Button engraving rate.

In order to quickly change the process gas group supplied to the process chamber, it is necessary to avoid a large change in the 3 = MFC set point. In a preferred embodiment of the invention, the MFC can be set at (4) and deposited to maintain a near-fixed degree while maintaining the degree of freedom in the process steps " See Figure 丨. In the new architecture, open the abandon chamber inlet valve 4 and close the gas A (10) chamber bypass valve 2, and enter the first gas (gas A) 10 metered into the process chamber i . In the process step requiring gas A (10) without gas β 〇 2), the gas Β chamber bypass valve 8 is closed and the gas Β chamber population valve 6 is closed to 3 gas amount of gas β (1 2 ) Directly to the discharge pipe 2 〇, see Figure 2 (:). The discharge tube of the chamber may be the chamber of any suitable low-retent chamber outside the reaction zone within the chamber for the chamber volume of the process gas to react with the substrate. 16 1305664 遐JJ rn Example of Process Procedure for Body A(10)" Using this gas delivery architecture, the gas chamber A can be opened by simultaneously opening the gas chamber A bypass valve 2 and the β body β chamber inlet valve 6 And simultaneously close the gas A chamber inlet valve 4 such as > μ 4 and the rolling body β chamber bypass valve 8, and the chamber 14 is switched from the process gas eight (10) to the process gas B. (1) The gas 10 or 12 always flows to the sputum, and the U table is out of the official. It does not flow through the chamber 14 or flows through the bypasses 16 and 18, so it is difficult to hide. The MFC of 1〇 and 12 can be set at a specific process setting, and will not be held by LN. It will be in the process of the process of oxygen in the state of “off, (#踗). The total ^ is ... ° and 12 to form a back pressure. Value 22:, the example of circle i shows the chamber bypass gas flow

All can be diverted to any suitable; any chamber bypass gas flow 16 and W cycle time is between! The cycle below the number to the negative cycle can be 99%, the total [implementation] == two-body example in the 'gas switching frequency can be discontinuous in the process time = line frequency can be one or more in the process It is worth noting that the M process is continuously performed. It is also shown that the pulse can be generated using a gas sample of the present invention. The principle of the same way and the principle of pumping allows any quantity of gas to be processed by another process, wherein the invention can be applied to the use of a plurality of gases - the process gas flow does not generate veins during the process of processing 17 1305664 . From the beginning to the end of the entire process, the continuous flow rate of the gas can be maintained constant, or the conventional MFC can be changed discontinuously or continuously throughout the process and at least one gas can be pulsed using the present invention. The continuously flowing gas can be Same as one of the gases that generate the pulse.

As is known in the art, the etching or deposition portion (or both) of the process cycle can be divided into a plurality of segments. One example is to divide the etched portion of the cycle into two segments to optimize the first etch. a circulation section to remove the protective polymeric film on the horizontal plane from the previous sinker (typically using a higher swollen bias power), while the second etch cycle section can be optimized to achieve a high Si shift The rate of removal (typically at higher etch process pressures, higher reverse gas flow, 4 higher plasma density). Therefore, the present invention is used for the division. It is also advantageous to have a multiplex process in which the pulse process gas MFC flow rate is not changed within the zone, or between zones. The invention may also be used with other time-division multiplex parameters, such as RF power, and/or any other process parameters, which may be in-phase or out-of-phase with a discontinuous gas (4).仃 Time-division multiplex, other time multiplex parameters are not limited to gas cutting _

Using the present invention, the process gas composition can be interrupted by a shut-off valve in one second: in the present invention, the process chamber residence time, rather than the valve response, is caused by: TM money engraving the minimum period of time possible. The chamber's residence time can be short, low process pressure, increased process gas flow, or reduced chamber volume. By placing the isolation valve close to the process chamber gas delivery port. The residence time of the second branch tube is minimized, and the manifold volume between the isolation valve and the: minimizes the residence time of the gas manifold. ^ 18 1305664 Another advantage of the present invention is that its total gas flow is relatively stable compared to the gas flow architecture of a conventional commercial electro-destruction device, and there is no pressure behind the gas in the MFC because it is always "on". This avoids pressure "flushing out" when the gas composition changes. It can obtain better control ability and stability. The invention described here can be applied to high-density plasma etching processes, such as ICP (induced coupling plasma), ECR ( Electron cyclotron resonance), or a low-density system such as reactive ion #1 (1 £1), the gas switching method can be applied to an etching process that requires one or more gases to change over time. It is also important to note that even though the method is exemplified by deep Si etching, it can be used to etch other materials, such as dielectric materials and metals, which require a rapid change in the composition process in a short time scale. Referring now to Figure 2(ad), which is a preferred embodiment of the present invention, which uses a method of 25 sccm c4F8, 80 sccm%, 2〇w rie and 12_icp to engrave the substrate, the _MFC gas stream The set amount, process house force and temperature Xiao RF power are kept constant throughout the whole process, and the cyclic load is maintained at 50%. The actual gas switching time is deposited in the figure for W seconds and 10 seconds, which is 5 seconds in Figure 2 (8). The button engraved with the second deposition, 2.5 seconds for 2.5 seconds in Figure 2(c), and deposited at _ 2(4), :::/1:5 seconds. When using a fairly long deposition/etch cycle, ...the sector 3 on the wall 32 is more pronounced than the trench 3

I:::, and when using the fast gas switching of the present invention: large, as shown in (4) and 2 (4). The high-resolution M photograph shown in Fig. 3 shows that the maximum shape of the deposition process is 1.5 seconds as shown by 2(4)/U 19 1305664 seconds, and the peak to peak (10), the depth from the peak to the bottom is about 3 〇. ^ Intentionally, the system and the body cut 槌眸μ μ, the south etch rate of 5 〇 can be maintained until the gas entanglement 52 approaches the gas residence time in the chamber, as shown in Figure 4 / 2 ^ ^ insect 710 The cycle time of the second deposition is 56 to 2.5 seconds, the quotation is 2:?, the cycle time of the deposition is 52, and the fan amplitude is ", but the etch rate is 5 〇, which remains near the upper ώΙ 71 _ at f 亘疋 3 / / min, using 1 · Except for the 5 second etch/U sec deposition process, the _ rate is reduced by 5q%. The calculation of the chamber shows that this is the actual 々 - the experimental rolling body retention time is about 1.5 seconds. When the milk switching cycle time 52接#μί_ ώ 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士 士,:;=^古* 』Feng 50 will increase with the gas flow rate and increase it. It is independent of the gas switching frequency under the fixed power cycle. I will understand that the specific description of the invention described and described here is only Exemplary variations, variations, alterations, and equivalents may be made without departing from the spirit and scope of the invention. Anyone who is familiar with this technology thinks about it. Therefore, all of the descriptions here and below: The purpose of this article is to use only the meaning of the object of the Λ兮昍天田二外闽1 as a description, not a limitation. The scope of the present invention is determined by the scope of the appended patent application. [Simplified illustration of the drawings] (1) Figure 1 (ab) is a schematic diagram of a gas bypass path operation 20 1305664 of a preferred embodiment of the present invention; (ad) is a schematic diagram of the fan-shaped amplitude and the progressive reduction caused by the shortening of the gas circulation time in the etching process; FIG. 3 is a high resolution of the reduced fan shape as shown in FIG. 2(d) by the preferred embodiment of the present invention. Figure 4 (ab) is a schematic diagram of the overall etch rate versus gas cycle time and fan amplitude versus gas cycle time. (2) Component symbol 2 Chamber bypass valve 4 Chamber inlet valve 6 Chamber inlet valve 8 Chamber bypass valve 10 Process gas 11 MFC 12 Process gas 13 MFC 14 Input process chamber 16 Bypass 18 Bypass 20 Discharge pipe 21

Claims (1)

Predicate :) 止尽 j > Preparation, patent application scope: 1. A device for improving gas switching, the device comprises: a plasma chamber; at least one plasma source for generating a plasma in the plasma chamber; a substrate holder located in the plasma chamber; an etching gas supply having an associated gas inlet for supplying an etching gas to the plasma chamber, and an associated gas bypass for discharging the silver engraving gas, a deposition gas supply having an associated gas inlet for providing a deposition gas to the plasma chamber, and an associated gas bypass for discharging the deposition gas; and a gas control switch for controlling the gas At least one of the etching gas supply and the deposition gas supply such that the gas inlet of the at least one gas supply and the gas bypass structure are such that the gas flow bypasses the electric pumping chamber when the gas inlet is closed. 2. The apparatus of claim 1, wherein at least one of the etching gas supply bypassing the plasma chamber and the deposition gas supply is introduced into the plasma chamber discharge tube. 3. A gas supply system for supplying gas to an alternate deposition/etching chamber for fabricating a semiconductor, the gas supply system comprising: a mass flow controller for providing a gas stream; a gas inlet for The gas of the mass flow controller is introduced into the deposition/etching chamber; and a gas bypass is used to discharge the gas to the mass flow controller 22 when the gas inlet is closed. 4. The gas supply system of claim 3, wherein the gas further comprises an etching gas. 5. The gas supply system of claim 3, wherein the gas further comprises a deposition gas. 6_ The gas supply system of claim 3, further comprising a discontinuous gas switch for controlling a gas flow from the mass flow controller such that a gas flow from the mass flow controller is At the gas inlet Switching alternately with the gas bypass. 7. A method of controlling a gas flow from a mass flow controller to a semiconductor via cavity to maximize sidewall smoothness of an etched trench on a substrate, the method comprising: providing a control from the mass flow a specific gas flow; supplying the gas flow from the mass flow controller directly to the semiconductor manufacturing chamber in a gas operating state; The gas stops working and the gas flow from the mass flow controller is diverted directly to the discharge tube of the semiconductor manufacturing chamber. 8. The method of claim 7, wherein the gas flow is diverted from the chamber in a gas-operated state to maintain a constant pressure of the gas at the outlet of the mass controller. 9. A method for anisotropic plasma etching of a chamber, the groove structure defined from the side, and having smooth sidewalls therein, the method comprising: reactive gas engraved gas to the first gas Working status, directly provided - 23 1305664 flushing into the chamber to etch the crucible while alternately operating in the second gas state, directly providing a reactive polymerization gas pulse to the chamber to deposit a polymerization layer; after the first gas is stopped, via A reactive gas bypass directs the S-reactive etching gas directly to the discharge officer in fluid communication with the chamber, and the second gas is stopped, and the reactive polymerization gas is directly diverted via a polymerization gas bypass. The discharge tube to the chamber; contacting the ruthenium with the reactive etching gas in a first gas working state in at least one etching step to plasma etch one surface of the crucible, and shifting the surface of the crucible Forming an exposed surface; contacting the ruthenium with the reactive polymerization gas in a second gas working state in at least one polymerization step to polymerize at least one polymer to the surface of the crucible while covering with a polymeric layer The surface exposed in the previous etching step thus forms a temporary etch stop; and the etching step and the polymerization step are alternately repeated. The method of claim 9, wherein the reactive etching gas pulse is a discontinuous pulse generated in the etching step. The method of claim 9, wherein the reactive polymerization gas pulse is a discontinuous pulse during the deposition step. 12. The method of claim 9, further comprising maintaining the reactivity substantially at the outlet of a reactive f-flow controller during the first gas operating state and the first gas shutdown state The surname is engraved with a certain pressure. 13. The method of claim 9, further comprising maintaining the second gas working state of the reactive polymerization gas and the first reactive polymerization at one mouth during the 24 1305664 two gas shutdown state The mass flow controller is produced at a certain pressure. . The method described in Item 9 of the patent yoke of the month, in which the etched $ 于 包含 包含 包含 包含 包含 变换 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , substrate bias, residual rate, mussel t, cycle time, and etching/deposition time ratio. - 1 or 5:::: The method of claim 14, wherein the transformation ', the number is implemented in each process cycle. 16. If the method described in claim 14 is applied, one or more parameters are implemented in the process cycle. ...the method described in the exchange item's further includes the step of, the reactive etching gas is made of -1 1 · If the patent scope of the patent clears the g-th step: with an essence of [5! - u + ten shells The rate flow controller is turned out. 18. As in the patent application form, an essentially fixed flow controller is rotated. The method of claim 9, which further comprises a rate of the reactive polymeric gas from Pick up, pattern: like the next page