TW200401946A - Process for etching photomasks - Google Patents

Abstract

Method and apparatus for etching a metal layer disposed on a substrate, such as a photolithographic reticle, are provided. In one aspect, a method is provided for processing a substrate including positioning a substrate having a metal photomask layer disposed on a silicon-based material in a processing chamber, introducing a processing gas at a flow rate of greater than about 350 sccm with the processing gas comprising an oxygen containing gas, a halogen containing gas, and optionally, an inert gas, into the processing chamber, generating a plasma of the processing gas in the processing chamber, generating a bias of about 50 watts or less, and etching exposed portions of the metal layer disposed on the substrate.

Description

200401946 发明, Invention: Description: [Technical Field to which the Invention belongs] The present invention relates to the manufacture of integrated circuits' and is related to the manufacture of lithographic photomasks for integrated circuit manufacturing industries. In addition, this case claims all the benefits of U.S. Provisional Patent Application No. 60 / 374,239 (filed on April 19, 2002), which is incorporated herein by reference.

[Prior art] Since the first creation of geometric patterns in semiconductor devices more than a decade ago, there have been remarkable achievements in size reduction. Since then, the integrated circuit has roughly halved in size every two years ~ .........

Moore ’s Law), which means that the number of transistor components on a wafer doubles every two. Today's manufacturing equipment routinely produces devices with a characteristic size of 0.15 μm to 0.13 μm, and future manufacturing equipment will soon reproduce even smaller geometries.

Increasing circuit density has become an external requirement in the manufacture of semiconductor devices. For example, when the circuit density increases, the visibility of through holes, contact windows, other characteristics, and the dielectric materials therebetween will be reduced to the sub-micron size, and the thickness of the electrical layer will be maintained-a constant, so these features are highly effective. Shape: ie? (Divided by a high ratio) will increase. It is also very important for these high aspect ratio features to be “close to individual substrates” and to be “off”.

According to the convention; ^; ,, the formation of the surface of the Xuanxuan L / wood width ratio features are patterned by the United States Yiyi the size of these features, and then the substrate is etched to remove the 200401946 material and the aspect ratio definition Therefore, the effective technique, or the special layer of the special process, the wiring light to the desired line of light should be the substrate material surface is not quartz or light-transmissive and define these characteristics. In order to form a desired height / width ratio of these height and depth features, the dimensions of the features must be formed within a certain number of parameters (generally the critical dimensions of the features). If high-aspect-ratio features with the desired key dimensions can be formed, it is necessary to accurately pattern and the subsequent substrate. Lithography is a technique used to form precise patterns on the surface of a substrate, and the patterned surface of the substrate is engraved with money to form the desired device feature. Lithography technology uses a light template and a photoresist material, which are deposited on the surface of a substrate 'before being carved to develop the solutions on the surface of the substrate. In the traditional lithography process, a photoresist is applied to the features to be etched and the features to be etched in the layer, such as contact windows, through holes or connections, etc., are placed on top of it by a photomask layer. The lithographic mask plate defines the manner in which the photoresist is exposed to a light template, and the mask layer corresponds to the configuration of the features. A light source emits ultraviolet (Uv) or low X-rays, which can be used to expose the photoresist to change the composition of the photoresist. Generally, the exposed photoresist material is removed by a chemical process to expose the underlying material. The exposed lower substrate material is etched to form the features on the United States, and the remaining photoresist material continues to serve as a protective coating for the exposed lower substrate material. … Lithographic masks generally include a substrate made of an optically transmissive silicon-based material (ie, silicon dioxide, Sit), and an opaque layer of a mask (typically chromium) On the surface of the substrate. ^ The layers are patterned corresponding to the features to be transferred to the substrate. In other words, the traditional lithographic mask is firstly deposited on a substrate.

4 200401946 layer, the substrate has at least one photoresist layer and the critical dimensions of the laser or electron beam layer. The patterned photomask of the protected metal falls on the surface of the substrate. Known etching | It will cause the undercut to appear: features, and these special features will make the isotropic etching. }] (overetch) 3 If the metal layer is not penetrated, and it is required for subsequent plasma etching, it will provide the image of wet etching anisotropic etching, and it can enhance the plasma of the now straighter side wall etching gas. The gas (such as helium) includes an optically penetrable silicon-based material (such as quartz), which is deposited on the thin metal layer and the k λ layer. The first blocking and then using Xi and other patterning equipment to determine The material is thus exposed and # 彡 $ _ layers. These light leather layers allow light to pass through-with a precise pattern. : Process (such as wet etching) tends to be isotropic etching, and the metal layer under the patterned photoresist has a bottom + knife · I. The undercut phenomenon produces a number of patterns on the reticle that are not evenly spaced and do not have the desired strokes. The critical dimensions of these features fail. In addition, these features may cause over-etching of the sidewalls of the feature at that aspect ratio and cause critical dimensions of these features to fail. Forming these desired key size features will be detrimental to the photolithography process. It will not be possible to form the desired pattern with a photomask. Known processes such as dry etching or dry etching can be performed in accordance with another option and A wet etching process is a better choice. The dry etch process has been proven to reduce the maintenance of critical dimensions of mask features such as undercuts, and to bring them to a better bottom. In the conventional dry etching process, a metal gas such as chlorine gas, oxidizing gas (such as oxygen), and inert is used to etch the metal layers formed on the substrate.

5 200401946 The etching gas system is introduced into the processing system at a flow rate of less than 300 seem to etch the mask plate of the conventional mask. An oxidizing gas (such as oxygen) will cause over-etching or inaccurate etching of the sidewall of the opening formed on the photoresist material, and the opening is used to define the critical dimensions of the metal layer. Excessive sidewall removal of the photoresist material will result in the loss of critical dimensions of the patterned features, which is comparable to the loss of the critical dimensions of the features, and the features are formed by the patterning

On the metal layer defined by the photoresist layer. It has been observed that an increase in the flow rate of the etching gas causes excessive etching of both the photoresist material and the substrate. A method for solving the excessive #etching is to reduce the amount of the remaining gas or reduce the concentration of the etching gas in the plasma formed for dry etching. However, these compositions have been found to be insufficient to etch the features to provide these necessary critical dimensions. The failure to adequately leave these key dimensions here is referred to as an "increase" in these key dimensions. The extent to which these critical dimensions are increased or lost within the metal layer is referred to as "residual deviation" or "critical dimension deviation". The etching deviation on the mask pattern can be as large (many) as possible to form a feature of 0.14 μm on the surface of the substrate.

The mismatch or increase of the key dimensions of the pattern formed on the metal layer is not conducive to the passage of light, and it will cause a lot of pattern defects on the substrate that is accumulated by the lithographic mask plate and cause a lot of pattern defects. After the money was scarce. , Said. The loss or increase of the key size of the child mask will result in insufficient lithography effects of etching the sub-micron features, and if the loss of these key dimensions, Tianshuang increases the situation, it will be very serious. Photomask or subsequent etching device ^ A method to protect the critical dimensions of a feature is to use the process gas containing pure 6 200401946 J d »1 >% | (side wall /, such as hydrocarbons), which can be used in Of these features > Form two-molecule deposits and avoid over-etching. However, knife-shaped compounds may deposit on processing chamber parts and be processed until they become a source of particulate matter. Particulate matter can be deposited on the surface of the substrate, which is quite detrimental to the remaining processes and subsequent processing. Therefore, there is a need for a process and a chemical action, which can etch a metal layer on a substrate (such as a photomask) to produce a pattern with a desired key size on the metal layer. [Summary of the Invention] The aspect of the present invention generally provides a method for etching a metal layer deposited on a silicon-based substrate (such as a lithographic photomask) and related chemical effects. In a specific aspect, a method is provided for processing a lithographic reticle, the method comprising positioning the reticle on a support element in a processing chamber, wherein the reticle includes at least one formed on A metal photomask layer on a silicon-based substrate, and a patterned photoresist material deposited on the metal photomask layer; a flow rate of about 30 sccm is introduced into a process gas, wherein the process gas includes at least An oxygen-containing gas and a tooth-containing gas; transmitting power to a diagnosis and treatment room to generate a plasma of the process gas; providing a bias power of about 5 watts to the supporting element; and removing the metallic light The exposed part of the cover. In another specific aspect, a method is provided for processing a lithographic mask plate, the method comprising positioning the mask plate on a first and second element in a processing chamber, wherein the mask plate is at least Contains one formed in an optically pierceable 7 200401946

JkJl ·】 shirt | * The above-mentioned photomask layer and a patterned photoresist material deposited on the chrome-based photoresist layer and introduced at a flow rate of at least 3 5 Osccm to contain ^ containing gas and oxygen The process gas, in which the Mohr ratio between the chlorine and oxygen is between about 1: 1 and 5 and 4: 1, and the pressure of a processing chamber is maintained at about 2 mTorr and 50 mTorr Between; transmitting about 1000 watts or less of power (power) to a coil provided in the processing chamber to generate an electric mass; supplying a bias power of about 5 watts to the supporting element; etching the The exposed portion of the chrome-based photomask layer; and removing the chrome-based photomask layer with a removal ratio of a chrome-based photomask layer to the photoresist material of about 1.1 or higher. In another specific aspect, a method is provided for processing a reticle, the method comprising positioning a reticle on a support element in a processing chamber, wherein the reticle includes at least one formation A chromium-based photomask layer on an optically transmissive stone-based material and a photoresist material deposited on the chromium-based photomask layer; introducing at least one inert gas, a halogen-containing gas, and an oxygen-containing material The first process gas of the gas, wherein the flow rate of the tooth-containing gas and the oxygen-containing gas is about 100 sccm or less; and a power source (power) of about 1,000 watts or less is transmitted to a power supply provided in the A coil in the processing chamber generates a plasma; a second process gas containing at least a halogen-containing gas and an oxygen-containing gas is introduced, wherein the flow rate of the tooth-containing gas and the oxygen-containing gas is at least 3 50 sccm Transmit a power supply (power) of about 10,000 watts or less to a coil provided in the processing chamber to maintain an electric convergence; supply a bias power supply of about 5 watts to the support Element; and exposed by etching the chrome-based mask layer Minute. 8 200401946 [Embodiment] The present invention I will be described in the following including a discrete plasma source, which is processed by San ETEC, California (ETEC, ETEC, other types of processing chambers, magnetic plasma etching processes, etc.) Considered in this case. Although the implementation of these | processing chambers is limited to Figure 1, it can be used to implement a cylindrical side energy penetrable (the bottom of the chamber 17. One instead of the round cover around the The round hood processing chamber 10 is located in a state where the round hood 13 is too inductive to fit the plasma plasma processing chamber. The appropriate inductively coupled plasma etching processing chamber package (Decupled Plasma Source (DPSTM) processing chamber). , Listed by TAKLALA American Applied Materials Co., Ltd .; or Teuaw) photomask etching processing chamber, which is listed by California Sea Company. The processing chamber can also be used, such as capacitively coupled parallel plate strong ion etching processing chamber and Differently designed inductive coupling chambers. Examples of such suitable processing chambers have been disclosed in US Patent Application No. 09/325, 〇26 applied by M ”, a w, 7Γ π and a DPSTM processing chamber in + 1 pass. Better operation, However, the description with Df is for illustration and should not be regarded or interpreted as the scope of the system. ^ The processes described here. The wall of the processing chamber 10 or the main body of the processing chamber 12, an energy transparent fixed to the body ) Of the round cover 13 and a flat cover (not shown) or other optional cover that can be used as an induction coil to tilt 13. At least a part of the induction coil 1 3. The processing chamber body 1 2 γI The bottom of the chamber 17 can be made of a metal (such as an electroplated inscription), and can be made of an energy-permeable material, such as

9 200401946 Other dielectric materials. A substrate supporting element 16 is disposed in the processing chamber to support a substrate 20 during a process. The supporting element 16 is a conventional mechanical or electrostatic adsorption base, and at least a part of the supporting element 16 is conductive and can be used as a process cathode. At the same time, a photomask adjuster (not shown) can fix the photomask on the supporting member 16. The mask adjuster generally includes a lower portion to cover a higher portion of the supporting element, and a whisker portion having an opening of a suitable size to support the mask. _A suitable mask adjuster has been disclosed in U.S. Patent No. 6,251,17 (issued on June 21, 2001) 'which is consistent with the claims and implementation aspects of this case and incorporated herein as reference. The process gas systems are fed into the processing chamber 10 by a process gas source via a gas distributor 22 (about the periphery of the support element 16). For these mixtures of process gases, a mass flow controller (not shown) of each process gas is provided between the processing chamber 10 and the process gas source to adjust each flow rate of the process gases. These mass flow controllers can increase the flow rate of each process gas or process gas mixture to about 1000 scem. The electric area 14 is defined by the processing chamber 10, the substrate supporting element 16 and the dome 13 and the like. The power source VII produced by a coil power supply 27 is supplied to the induction coil 26 and an electromagnetic field is generated in the electropolymerization region 14 so that the process gases form a plasma in the plasma region 14. The supporting element 16 includes an electrode provided therein, which is driven by an electrode power supply 28 and generates a capacitive electric field in the processing chamber 10. Typically, the δ RF power is applied to the electrode of the component 16 of the building. At the same time as 200401946, the body 12 is electrically grounded. The capacitive electric field is transverse to the plane of the support element 16 and will affect the directivity of the charge to make the substrate 20 more vertically anisotropic.

The process gases and by-products of the etchant are discharged from the processing chamber 10 through an exhaust system 30. The exhaust system 30 may be provided at the bottom 17 of the processing chamber 10, or may be provided at the main body 12 of the processing chamber 10 to remove the process gases. The exhaust port 34 is provided with a throttle 32 for controlling the pressure of the processing chamber 10. An optical endpoint measurement device can be connected to the processing room 10 to determine the end of the process operated by the processing room. Although the following process description describes an embodiment in which a substrate is etched using a process gas, the present invention considers process parameters that are used outside of the range described herein so that it can be used in different equipment (such as a different The remaining processing room) operates this process and processes substrates of different sizes (such as lithographic photomasks for 300mm substrate processes). Exemplary Etching

A typical lithographic mask plate includes a metal layer (such as chromium or chromium oxynitride) deposited on an optically transmissive substrate, which is known as a mask. The metal layer is etched to form a photomask layer having the desired key size features. A process gas includes an oxygen-containing gas and a tooth-containing gas for etching the metal layer, and the process gas may include an inert gas, and the flow rate of the process gas is greater than about 300 sccm. The exposed metal material is etched by generating a plasma of a process gas, and a bias voltage provided to the photomask is higher than 5 watts. Prior to the introduction of a process gas of the composition and flow rate described herein (for the etching process), 200401946, plasma impingement may be used to form the plasma. The exposed metal layer etched by the etching process described here unexpectedly presents minimal etching deviation, vertical etch contours and forms openings, and the patterns have the desired critical dimensions.

The process gas may include an oxygen-containing gas and a tooth-containing gas. The oxygen-containing gas includes oxygen (02), carbon monoxide (CO), carbon dioxide (co2), and mixtures thereof, and among them, oxygen is preferred. The oxygen-containing gas provides a source of etching radicals. These carbon- and oxygen-containing gases provide a source of material to passivate polymer deposition, which can improve etch bias. The tooth-containing gas may include the chlorine-containing gas selected from the group consisting of gas (Cl2), carbon tetrachloride (CC14), hydrochloric acid (HC1), and combinations thereof. Among them, chlorine gas is preferred. It is used to provide highly reactive radicals to etch the metal layer. The chlorine-containing gas provides a source of etching free radicals, and the carbon-containing and chlorine-containing systems provide a source of material for forming a passivated polymer deposit that can improve etch bias.

The tooth-containing gas and the oxygen-containing system are provided in a molar ratio between the tooth-containing gas and the oxygen-containing gas of about 1: 1.5 and 4 ·· 1, for example, the molar ratio of chlorine / oxygen is about 2.7: 1 . And if the process gas is converted into a percentage of the total number of moles, the halogen-containing gas is generally between about 40% and 80%; and it has also been found that the halogen-containing gas having a concentration between about 50vol% and 70vol% can provide orders. Satisfactory etching effect. The process gas may also include an inert gas. When ionized to form a part of the plasma (including the process gas), sputters are formed and the etching rate of these features has been increased. An inert gas that becomes part of the plasma also improves the dissociation of the reactive process gas. Examples of the inert gas include argon (Ar), helium (He), neon (Ne), xenon (xe), krypton (Kr), and combinations thereof, and generally argon and helium are used. In the inert gas, the molar ratio of the oxygen-containing gas to the inert gas is between about 0.5 ·· 1 and 1: 1. For example, the molar ratio of helium to oxygen is about 0.7 · 1. The general volume percentage of the inert gas is between about 5 vol% and 40 vol%. For example, the total gas flow used in the process is between about 15 vol% and 25 vol%. A "strike" gas between about 75 vol% and 25 vol% of an inert gas volume percentage can be used to start the plasma before the etching gas is introduced. The total flow rate of the process gases (including the inert gases) is extracted at a flow rate of approximately greater than 300 seem, for example, the process gas system in an etching processing chamber is extracted at a flow rate of approximately 300 sccm and 1000 scccrn. Etching a 150mm X 150mm square lithographic mask plate. Process gases with a total flow rate between about 400 seem and 700 seem can be used in the etching process described herein. However, the total flow rate of the process gas (including the inert gas) can be modified according to process factors such as the size of the processing chamber, the size of the substrate to be processed, and the specific etching profile required by the operator. The tooth-containing gas system was introduced into the process at a flow rate of at least 200 sccm so that a 150 mm x 150 mm square lithographic mask was engraved in the remaining processing chamber. The halogen-containing gas can be used in the remaining processes described herein at a flow rate between about 200 scccrn & 600 sccm. Each of the oxygen systems was introduced into the processing chamber at a flow rate of at least 100 sccin and etched with a 150 mm x 150 mm square lithographic mask. Generally speaking, the oxygen-containing gas flow rate used in the etching process described herein is at least 13 200401946 150 sccm (eg, between about 15 scccin and 400 scccni). Generally speaking, the pressure in the process chamber of this process is maintained at about 2 Torr to 50 Torr, and the pressure of the processing chamber during etching is maintained at between about ^ Torr and 35 mTorr (about 15 mTorr and 32 millitorr: 2

The substrate temperature during the manufacturing process is about 150 ° C or lower. Temperatures below 15 ° t or lower have the lowest solution to materials (such as resistive materials), and the materials are deposited on the substrate during the manufacturing process of lithographic photomasks as described in H ^ . The substrate temperature between about 20t and l50 (> c (preferably between 20c and 50 ° C) can be etched with the minimum thermal decomposition of the material The characteristics of the mask placed on the substrate surface. It is generally believed that the substrate temperature during the etching process can limit the polymerization reaction to help control the formation of passivated polymer deposits. In addition, the sidewall of the processing chamber is kept approximately low At a temperature below 7 ° C, and the dome is kept at a temperature below 80 ° C to keep the process conditions consistent and minimize the polymer composition appearing on the surface of the processing chamber.

During normal etching process, it will be one of about 1,000 watts or less RF

The power stage is applied to an induction coil to generate and sustain a plasma of these process gases. It has also been found that power levels between about 300 watts and 1,000 watts (e.g., about 650 watts) can provide sufficient plasma for these process gases to etch the surface of the substrate. The listed RF power levels have been found to produce sufficient etch radicals and radical polymerization reactions in these process gases to etch the exposed metal layer deposited on the substrate 'while providing a sufficiently low (compared with conventional metal etching) (Compared to the manufacturing process) to allow the substrate temperature to be about 150 ° C or lower. Generally speaking, a bias power source of less than 200 watts is applied to the substrate 14 200401946 to directly increase the directivity of etching radicals on the surface of the substrate. Bias power supplies below 50 watts (for example between about 20 watts and 40 watts) can also be used in this etching process. During this etching process, it has been found that a bias voltage between about 25 watts and 35 watts can provide sufficient directivity of the free radicals at the rest. It has also been unexpectedly found that the process gas flow rate is greater than about 30 sccm, and the bias power is greater than about 5 watt-hours (for example, between about 20 watts and 40 watts). The etched metal layer will have a vertical etch profile. And the obtained openings and patterns and the conventional etching process (flow rate below 300 sccm or lower and low bias power supply about 5 watts or lower, the key dimensions obtained are better; also _ surprisingly found that The above-mentioned effects can also be obtained in the absence of a passivation gas used in conventional techniques. The etching processes described here can obtain a metal layer / photoresist with a shift of about 1: 1 or higher under the conditions disclosed. Removal ratio (ie, selectivity or last name deviation). It has been found that substrates treated with the etching process described herein have a chromium to photoresist selectivity of about 3: 1 or higher. Increased selectivity can protect The key dimensions patterned on the photoresist layer, and the etched chromium features can be made to the desired key dimensions. The etching process has also been observed. In addition to the characteristic photoresist material on the side, it is removed. "Top" or lower surface photoresist materials are produced with anisotropic etching and improved features Consistent. In addition, compared with Xi's technology, the characteristics of the key dimensions obtained from the treated substrate are almost vertical, that is, the angle between the sidewall of the feature and the bottom of the feature is about 90. The obtained by the conventional technique is about 85 ° to 88 °). It has also been observed that when etching the etched metal layers of such photomasks, the etch determined on the premises obtained with the nickname of Known 15 200401946 should not be passed by 1% or Understand the definition of different dimensions and resolution. Process points, the side features are carved: This process (ie, lower than the flow rate and bias power supply described here, J, compared to the improved micro load Effect, micro-negative effect, and ancient Xia linearity. The micro-loading effect defined by Tubu is broad, as is the difference in the etching rate of the same material placed or exposed with injustice (also g size feature, ^ p # 目 同 材料) After the exposure, the difference between the characteristics is 1μm wide and 100m). When the etch rate is similar to the feature of the same size, the improved microload effect is self-explanatory. The microload effect defined here is broader, such as Different number :, exposure material ㈣ 刻 ㈣ (that is, the difference between _ rate exposure on a substrate surface = 90% chromium). The improved micro-loading effect will be broadly similar for different amounts of exposed materials. ^ Here again The linearity is relatively broad, as the difference between the actual etched features and the desired or patterned features of the dimensional features (that is, the real inch 0.24 micrometers and dimensional features 1) Attacking the photoresist pattern with 0.24 micrometers of these features 1 micron of Mori, the difference between today and today, the improved straight line can be broadly geographically distinguished from the features of the patterned photoresist, with improved accuracy And repeatability It is generally believed that the plasma formed by the He Xuweng μ μ ceremonial system will remove the exposed part of the metal layer with an increased body flow rate and increased value. The openings (or patterns) formed on the _ # and the photoresist material are caused by the last name engraving, and it is recommended that those formed on the metal layer during the last name engraving can also do whatever they want. Key dimensions. In a specific aspect, an electric propeller (strike) can generate plasma in the processing chamber before the introduction of the rolling bodies for the etching process (which is performed in the required amount and concentration described herein). . It is believed that under the process conditions of the same power 16 200401946 level, the helium atoms are more easily ionized than the chlorine or oxygen atoms and the resulting plasma is more uniform. The ionization of helium allows an electric plutonium to be formed at a higher processing chamber pressure, a lower power source, and a higher bias power source, and a stable plasma will be faster than the tooth-containing gas and oxygen-containing gas. Way to form it. A plasma striking process gas generally includes an inert gas, as here

The milk-containing gas (not required) or the function-containing gas (not required) as described here. The plasma and process gas system are introduced into a processing chamber at a flow rate between about 300 sccin and 1000 sccm (eg, about 500 seem). When both the oxygen-containing gas and the halogen-containing gas are present in the plasma striking process gas, the flow rate of the combined gases is about 100 seem or lower than the total flow rate. The flow rate of the oxygen-containing gas may be about 100 sccm or less, and the flow rate of the halogen-containing gas may be about 100 seem or less. The molar ratio of halogen-containing gas / oxygen-containing gas is generally about 1: 1 or higher (for example, the molar ratio of chlorine / oxygen is about i. 3 3: 丨). The molar ratio of inert gas / oxygen-containing gas is generally about 3d or higher (for example, the molar ratio of helium / oxygen is about 5: 1). The gas flow rate can be introduced into the processing chamber in less than 30 seconds (eg, about 5 seconds) to stabilize the process gas flow rate. The pressure in the processing chamber is set between about 2 mTorr and 50 Torr, for example between about 20 mTorr and 30 Torr. Apply a power source to a coil in the range of about 300 watts and 1,000 watts (such as about 500 watts); and apply a bias voltage in the range of about 1 watt and 50 watts (such as about 20 watts and 40 watts) Between); the power used to strike the electricity can be less than the power used during the base side. These process conditions and the plasma conditions of the plasma striking process can be used in conjunction with the process gas described herein to estimate the etching processes, including the total flow 17 200401946 rate, processing chamber pressure, power source and bias current. ^ / H ^. The plasma striking process is about 15 seconds or less, such as between about 1 second and 5 seconds. An example of a plasma striking process is described below. A plasma striking process gas system containing at least helium, chlorination, and milk is about 秒 5 seconds, with a total flow rate of 480 sccm (wherein the helium flow rate (About 400 sccm, sc gas, rate of about 50 sccm, and oxygen flow rate of about 30 sccm) was introduced into the processing chamber ^ The pressure of the processing chamber was set to about 20 mTorr 'and a pressure of 500 was applied. The power of Wa Xifan and a bias power of 30 watts generate an electric shock in about 3 seconds.

The manufacturing process of the substrate may include a step of applying a power source to strike a plasma, and the power level is modified to meet the 4b etch-off condition, such as striking at 500 watts instead of 650 watts. A power supply; the power supply is secured, and the power supply is then stabilized, and then the etching process is performed. This power application step can be a leek, which is very short seconds, so that the last name on the surface of the substrate can be engraved. However, if the reactive oxygen-containing and tooth-containing process gases are adjusted to less than 1 () (^ _, the effect of radon will be reduced; in addition, the step will be lower due to the use of the process. The power level of the power supply reduces the etching effect. After the electropolymerization is hit, the process gas composition can be reduced by

The inert gas flow rate and the manner of increasing the flow rate of the tooth-containing gas and the oxygen-containing gas are modified into an etching gas composition. The following description will explain one embodiment of a process for successively etching metal layers (such as chromium and oxynitride). These metal layers are used as a photomask during the manufacture of lithographic photomask plates. After calculation, these etching gases can be used. It is used to etch other metal layers formed on the substrate during the manufacture of semiconductors and lithographic photomasks. FIG. 2 is a flowchart of an embodiment of a process of engraving a family name. This flowchart is intended to represent and should not be viewed as limiting the scope of the various aspects of the invention. 18 200401946 In step 210, a substrate including at least one of a silicon-based photomask (such as quartz with optical properties), molybdenum silicide, or molybdenum silicon oxynitride (Μ〇3ίχΝγ〇ζ) is provided to a processing chamber ( Such as DPSTM processing chamber 10 in Fig. 1). The substrate then deposits an opaque metal layer as a photomask layer (the photomask layer generally contains at least chromium), and the photomask layer is deposited on the substrate in step 220. In step 230, the openings or the pattern size 'to be patterned on the metal layer can be exposed to the metal photomask layer by depositing and patterning a first photoresist material. These photoresist materials used in the manufacture of lithographic photomasks are usually low-temperature photoresist materials, and the ones defined here are those materials that will be thermally decomposed at about 250 ° C. The photoresist materials can be optically patterned (ie, the photoresist materials), or they can be patterned by other radiation energy devices such as an ion beam emitter. The openings and patterns are usually formed by etching the metal photomask layer to expose the underlying substrate, that is, using an oxygen-containing gas and a halogen-containing process gas with a flow rate of about 300 sccm 'and applying A step 240 ^ of a bias voltage above about 5 watts can be used to generate the plasma to etch the photomask layer. After the etching step, the remaining photoresist material will be removed. The substrate can be further processed (not necessarily) to etch the silicon-based material to serve as a phase-shift mask plate. The Shi Xiji material of the substrate is deposited for etching, and a second photoresist material 250 is pattern-etched on the metal photomask layer and the silicon substrate portion is exposed. The substrate is then transferred to a DPSTM processing chamber where a sigma-containing process gas used to etch the silicon substrate is introduced into the processing chamber and an electric mass is generated to etch (260) 19 200401946 the substrate Exposed broken substrate. An example of a silicon-based photomask that etches the substrate includes using a process gas containing at least decayed carbon as the remainder. The process gas containing at least carbon fluoride contains 1 to 5 carbon atoms and 4 to 8 carbon atoms. Fluorine (including CIV, C4F6, C3F8, C4F8, C5F8) and combinations thereof. The fluorine-containing process gas system is introduced into a processing chamber (such as the aforementioned DPSTM processing chamber) at a flow rate between about 25Sccm and 100sccm. It is maintained at a pressure between about 2 mTorr and 50 mTorr. An inert gas (not required) that enhances the money engraving process can be introduced into the processing chamber at a flow rate between about 30 Sccm and 150 SCCm. During the process, an RF power source (power) between about 50 watts and 200 watts was applied to the induction coil to form and maintain the plasma. A bias power stage (not required) of about 50 watts and 200 watts can be applied to the substrate support to improve the control of the remaining processes. During the engraving process, the substrate was maintained at a temperature between 50 ° C and 15 ° C. In addition, the sidewalls 15 of the processing chamber 10 were maintained at a temperature of less than 70. (: Temperature, and the dome is maintained at a temperature below about 80 ° C to maintain the consistency of these process conditions' to reduce the polymer formed on the surface of the processing chamber. The process described here uses The silicon substrate of the etching substrate is described in more detail in U.S. Patent No. 6,391,79 (issued on May 21, 2002), titled "Method and Equipment for Silver Engraving Mask", its content It conforms to the aspect of the present invention and is incorporated herein by reference. Figures 3 A-3E show the composition of the photomask before the etching steps, which also illustrates the process of the aforementioned Figure 2. The substrate 3 00 is typical It is made of quartz material 310 with optical characteristics and sent into a processing chamber; a metal layer 320 made of chromium 20 200401946 is placed on the quartz material 31 (see Figure 38). The deposition can be performed by conventional methods such as physical vapor deposition (pvD) or chemical vapor deposition (CVD). The thickness of the chromium layer 32 is generally between 50 nm and 100 nm. However, the thickness of the layer varies depending on the manufacturer's needs and the composition of the substrate material or metal layer. See Figure 3B, the substrate 3 〇 system is then sent to another processing chamber in one of the photoresist material layer M0 (such as "RIS TON" made by DuPont Chemical Co., or other similar materials, etc.) is deposited on the chromium layer 32, about 20 Thicknesses of 0 nm and 600 nm. The photoresist material 33 is subsequently patterned with a conventional laser or electron beam patterning device to form a first opening 325, which is used to define the formation on the chromium layer 32. The size of the second opening 335. The substrate 300 is then transferred to an etching processing chamber (such as the DPSTM processing chamber 10), and the chromium layer 32 is formed by a conventional metal etching technique or a new metal surfacing technique. An etching is performed to form the second opening 3 3 5 and the lower quartz material 310 is exposed, as shown in FIG. 3C. A process gas and a bias voltage as described herein are used to etch the metal layer on the substrate. An exemplary processing method is shown below. The substrate is set A process gas is introduced onto the support element 16 to form a plasma to etch the chromium layer 320. In one embodiment of the process gas, the process gas includes at least oxygen, chlorine, and an inert gas. The process gas system is introduced into the processing chamber with a flow rate between about 400 sccm and 75 Osccm. For example, a flow rate of about 460 sccm can be used during the etching process; oxygen can be about 21 200401946 Part 3 of the body-inducing media: Introduce the flow rate of the base material between 100 sccm and 400 sccm into the processing chamber (for example, about 120 sccm); and chlorine gas at a rate of about 200 sccm and 600 sccm A flow rate is introduced into the processing chamber (for example, about 270 seem); the inert gas (for example, helium) is introduced into the processing chamber at a flow rate between about 0 seem and 500 sccm (for example, about 70 sccm).

Generally speaking, the pressure of the processing chamber is maintained between about 15 mTorr and 32 torr (such as about 20 mTorr), and an RF power source of about 300 watts and 1,000 watts is used during the etching process. (Such as 650 watts) is applied to a sensing circle to generate and maintain the plasma of these process gases, and a bias power source between about 20 and 40 watts is applied to the substrate support. During the etching process, the temperature of the substrate is about 20 ° C. (: And 100 ° C. In addition, the side wall of the processing chamber 10 is maintained at a temperature below about 70 ° C and the dome is maintained at a temperature below about 80 ° C. The above The selectivity of the metal layer obtained by the metal etching process to photoresist is generally about 1 or higher.

Referring to FIGS. 3A-3C, after the etching of the chromium layer 320 is completed, the substrate 300 is transferred to a processing chamber. The residual photoresist material 33 is generally removed from the material 300 by an oxygen plasma process or other conventional photoresist removal techniques. Referring to FIGS. 3D and 3E, the substrate 300 can be further processed by etching the quartz material 3 10 to form a phase shift mask. In the step of etching the quartz material 310, the photoresist material 330 is removed, and a second photoresist material 340 is applied and patterned to expose the lower quartz material 310 of the second opening 335. The thickness of the deposited photoresist material is about 22 200401946 between 20 nm and 600 nm, but it can also be any thickness and it can be the same thickness as those of the features to be etched in the quartz material 3 10 to form The mask plate. The substrate 300 is etched to form a third opening 3 45 in the photoresist layer 34, the metal layer 320, and the quartz material 31o, and the second photoresist material 34 is removed. To form a patterned substrate surface 3 55. The patterned substrate 300 is then transferred to an etching processing chamber (such as the DPSw processing chamber 10) for plasma etching of the quartz material 31. The above-mentioned process gas composition and processing method can provide controllable etching so that the openings or patterns have the desired critical size, and the etching of the openings or patterns is generally anisotropic. The anisotropic process removes material deposited on the bottom of the openings at a higher rate than on the sidewalls of the openings. The combination of the flow rate and the bias voltage described herein can improve the etching anisotropy of the plasma etching process, thereby increasing the etching rate at the bottom of the opening (compared to the etching rate of the sidewall of the opening). An etching process that etches the sidewalls of the openings at a slower rate will not cause excessive etching of the sidewalls, so that the critical dimension protection of the etched openings is improved, and thus the etch bias is reduced. It is generally believed that during the deposition or substrate processing, these chromium layers deposited by physical vapor deposition technology or chemical vapor deposition technology will adsorb several pollutants (such as oxygen and nitrogen, etc.). The oxygen and nitrogen in the deposited chromium material are derived from chromium oxynitride, which is mainly concentrated on the upper surface of the deposited material (for example, the chromium oxynitride layer at 30% of the upper layer of the chromium layer is used as an anti-reflection coating for the substrate Layer to improve the patterning effect of the photoresist material. The chromium oxynitride thin film is more sensitive to oxygen radical etching than chromium thin films. Reducing the oxygen content of the process gas will effectively etch the chromium oxynitride surface ( Refers to the comparison with a large number of residual complex layers.) The present invention will be further interpolated by the following examples, but these examples are not intended to limit the scope of the patent claimed by the present invention. Made of—Mask of the substrate, which is preferably U-thick road mask layer is placed on it, the mask board is sent to a processing room for you to load r load Resistance deposition. — Tokyo-Oka male gL Photoresist ('a photoresist material or Tokyo Oka eight) also listed in Japan. Photoresist (or CAR) is deposited on " City's chemical magnification type in this chrome mask} * 姐 # radio or electron beam pattern The device is patterned and connected, and the thickness of the photoresist on the traditional thunder-chrome mask is between about 200nm and 400nm, and the chain is between 600nm and 600nm. (If it is about the same, it can be any desired thickness. Place the photomask in an etching place ~ it belongs to the etching processing room 10). The pattern 4 to the middle (as described above on the cathode holder of the DPSTM gold etching process chamber, and the substrate is also placed on the millitorr as previously described. By applying a power level of about ^ processing chamber pressure system is maintained A coil of about 20 is used to generate a plasma. An RF voltage source of 30 watts and 0 watts is induced to the surface of the substrate by applying a bias power of about 20 β to the cathode base. Room walls and circles The cover is cooled to a temperature below about C and 50 ° C. The treatment is engraved with the processing conditions. The etching of the openings is performed at a temperature of < t to maintain a stable corrosion. The following gas flow is performed: 24 200401946 oxygen (〇 2) — 120 seem gas (Cl2) — 270 seem helium (He) — 70 seem The total flow rate of the process gases listed above is about 460 seem. The etching process is performed for a sufficient time to form the metal layer on the metal layer. Some openings. Example 2

The mask plate was placed in a DPSTM metal etching process chamber as described above. The patterned substrate was placed on the cathode base of the etching process chamber, and the pressure of the process chamber was maintained at about 20 millitorr. An RF voltage source of about 650 watts is applied to the induction coil to generate a plasma. A 30 watt bias power was applied to the cathode base. The surface of the substrate is maintained at a temperature between about 20 ° C and 50 ° C. The walls of the processing chamber and the dome are cooled to a temperature below about 70 ° C to maintain stable etching processing conditions. The opening is etched with the following gas flow: oxygen (〇2) — 200 seem gas (Cl2) — 300 seem

Helium (He) — 40 seem The total flow rate of the process gases listed above is approximately 540 sccm. The etching process is performed for a sufficient time to form the openings in the metal layer. Example 3 A reticle is placed in a DPSTM metal etching process chamber as described above. The patterned substrate was placed on the cathode base of the etching process chamber, and the pressure of the process chamber was maintained at about 20 millitorr. An RF voltage source of about 650 watts is applied to the induction coil to generate a plasma. A voltage source of 25 200401946 30 watts was applied to the cathode base. The surface of the substrate is maintained at a temperature between about 20 ° C and 50 ° C. The walls of the process chamber and the dome are cooled to a temperature below about 70 ° C to maintain stable etching process conditions. The opening is etched with the following gas flow: oxygen (〇2) — 360 seem chlorine (Cl2) — 240 seem helium (He)-> 0 seem

The total process gas flow rate listed above is approximately 600 sccm. The etching process is performed for a sufficient time to form the openings in the metal layer. Example 4

The mask plate was placed in a DPSTM metal etching process chamber as described above. The patterned substrate is placed on the cathode base of the etching processing chamber, and the pressure of the processing chamber is maintained between about 20 mTorr and 30 mTorr. An RF voltage source of about 650 watts is applied to the induction coil to generate a plasma. A 30 watt bias power was applied to the cathode base. The surface of the substrate is maintained at a temperature between about 20 ° C and 50 ° C. The walls of the process chamber and the dome are cooled to a temperature below about 70 ° C to maintain stable etching process conditions. The etching of the opening is performed with the following gas flow: oxygen (〇2) — 180 seem gas (Cl2) — 480 seem helium (He)-> 0-40 seem The total flow rate of the process gases listed above is about For 660-700seem. The etching process is performed for a sufficient time to form the openings on the metal layer. 26200401946 The foregoing is about the exemplary implementations of the present invention. Other and further implementations of the present invention may Proposed under the basic scope of the invention, and its scope should be determined by the scope of patent application below. [Brief description of the drawings] In order to obtain the method of the present invention described in the foregoing and to understand it in more detail, the present invention (briefly described above) can be described in more detail with reference to the specific embodiment and the description of the additional drawings.

It should be understood, however, that these additional illustrations are only intended as a general embodiment of the present invention and are not intended to limit its scope, so other equivalent embodiments will be deemed to fall within the scope of the present invention. Fig. 1 is a schematic sectional view of an embodiment of an etching process chamber. Fig. 2 is a flow chart showing one of the subsequent embodiments for processing a substrate according to the present invention. Figures 3A-3E show continuous etching according to another embodiment of the present invention

Sectional view. 1 2 Processing chamber body 14 Plasma area 1 7 Bottom of processing chamber 22 Gas distributor 27 Coil power supply [Simplified description of component representative symbols 1 0 Processing chamber 13 Dome 1 6 Support element 20 Substrate 2 6 Induction coil 27 200401946 2 8-electrode power supply 3 2 throttle valve 300 base material 320 metal layer 3 30 photoresist material 340 photoresist material 3 5 5 base material surface 3 0 exhaust system 3 4 exhaust port 310 quartz material 325 first opening 3 3 5 Second opening 345 Third opening

28

Claims (1)

200401946 Pick up and apply for patent: Scope: κ — A method for processing a lithographic photomask. The zero-time at least includes: placing the photomask on a supporting element of a processing chamber. The photomask includes a metal light formed on a silicon-based substrate, premature growth, and a patterned photoresist material on the metal photomask layer; a process gas at least 300 sccm is introduced. Table 4 A process lice body, wherein the process gas includes at least an oxygen-containing gas and a gas containing gas; a power source is transmitted to the processing chamber to generate the process gas; and a bias voltage of about greater than about 5 watts is provided to the support element ; And removing the exposed portion of the metal photomask layer. Among them, the above-mentioned metallic light 2.The method as described in item 1 of the scope of the patent application, and the cover layer contains at least chromium, chromium oxynitride or a combination thereof. The method according to item 1 of the scope of the patent application, wherein the above-mentioned silicon 2 includes at least an optically transparent silicon-based material, the silicon-based material is 2 clips, molybdenum silicide, silicon molybdenum oxynitride, and combinations thereof. Selected in the group. 4. The method according to item 丨 of the scope of patent application, wherein the reduction rate is at least 100 sccm. I. The method as described in item 1 of the scope of the patent application, wherein the yield of the lactose-containing and glutamic acid emulsions is between about 150 sccm and 400 seem. 29 200401946 6. The method according to item 1 of the scope of patent application, wherein the oxygen-containing system is selected from the group consisting of oxygen, carbon monoxide, carbon dioxide, and combinations thereof. 7. The method according to item 1 of the scope of patent application, wherein the flow rate of the tooth-containing gas is at least 200 sccm. 8. The method according to item 1 of the scope of patent application, wherein the flow rate of the tooth-containing gas is between about 200 sccm and 600 sccm. 9. The method according to item 1 of the scope of patent application, wherein the flow rate of the process gas is between 350 sccm and 100 sccm, wherein the flow rate of the oxygen-containing gas is between 150 sccm and 400 sccm and the halogen-containing gas The flow rate is between 200 sccm and 600 sccm. 10. The method according to item 1 of the scope of patent application, wherein the mole ratio of the halogen-containing gas and the oxygen-containing gas is between about 1 ·· 1 · 5 and about 4 ·· 1. 11. The method according to item 1 of the scope of patent application, wherein the halogen-containing gas contains at least one gas-containing gas selected from the group consisting of chlorine, carbon tetrachloride, hydrogen acid, and combinations thereof. 12. The method according to item 1 of the scope of patent application, wherein the process gas further comprises an inert gas selected from the group consisting of helium, argon, xenon, neon, krypton, and combinations thereof. 30 200401946 1 3. The method according to item 1 of the scope of the patent application, wherein the flow rate of the inert gas is about 500 sccm or less. 14. The method according to item 1 of the scope of patent application, wherein the bias power source is applied between about 20 watts and about 40 watts. 15. The method according to item 1 of the scope of patent application, wherein the metal mask The layer and the photoresist material are removed with a metal photomask layer / photoresist material removal ratio of about 1: 1 and 3: 1. 16. The method according to item 1 of the scope of patent application, wherein the method for processing the photomask plate at least includes introducing a process gas into a processing chamber, and maintaining the pressure of the processing chamber at about 2 mTorr and about 50 Milli-torr, and maintaining the temperature of the photomask between about 20 ° C and about 150 ° C, and applying an RF power source of about 300 watts and about 1,000 watts to a processing chamber Coil to generate a plasma. 17. —A method for processing a lithographic reticle, the method at least comprising: placing the reticle on a supporting element of a processing chamber, wherein the reticle includes at least one formed on an optically transparent substrate. A chrome-based photomask layer on a silicon-based material and a patterned photoresist material deposited on the chrome-based photomask layer; introducing a 31 200401946 process gas containing at least chlorine and oxygen at a flow rate of at least 350 sccm, wherein The molar ratio of the chlorine gas and the oxygen gas is between about 1: 1.5 and about 4: 1; maintaining the pressure in the processing chamber between about 2 mTorr and about 50 mTorr; and about 1000 watts or Lower power is passed to a coil in a processing chamber to generate a plasma; a bias power greater than about 5 watts is applied to the support element; Etching the exposed portion of the chrome-based mask layer; and removing the chrome-based mask layer with a removal ratio of the chrome-based mask layer to the photoresist material of about 1: 1 or higher. 18. The method according to item 17 of the scope of patent application, wherein the chromium-based photomask layer comprises at least chromium, chromium oxynitride or a combination thereof, and the optically transmissive silicon-based material comprises at least quartz, molybdenum silicide, nitrogen Silicon molybdenum oxide or a combination thereof. 19. The method of claim 17 further comprising introducing an inert gas selected from the group consisting of helium, argon, xenon, neon, krypton, and combinations thereof. 20. The method according to item 17 of the scope of patent application, wherein the process gas flow rate is between about 350 sccm and about 1000 sccm, wherein the oxygen flow rate is between about 150 sccm and 4 0 sccm And the flow rate of the chlorine gas is between about 200 sccm and 600 sccm. 2 1 · The method as described in item 19 of the scope of patent application, wherein the flow rate of the inert gas 32 200401946 is about 50 0 s c c m or less. 22. The method of claim 17 in which the bias power source is applied between about 20 watts and about 40 watts. 23. The method according to item 17 of the scope of patent application, wherein the method for processing the photomask further includes introducing the process gas into a processing chamber, and maintaining the pressure of the processing chamber at about 2 mTorr and about 5 Between 0 mTorr, the temperature of the photomask is maintained at about 20 ° C and about 15 ° C, and an RF power source of about 300 watts and about 1000 watts is applied to the coil in the processing chamber. 24. The method as described in item 17 of the scope of the patent application, wherein the plasma transmitted to the processing chamber to generate a process gas further includes a plasma strike. 25. — Treatment A lithographic photomask method, the method at least comprises: A photomask is placed on a supporting element in a processing chamber, wherein the photomask includes at least a chromium-based photomask layer formed on an optically transmissive silicon-based material, and a chromium-based light deposit A patterned photoresist material on the cover layer; introducing a first process gas containing at least an inert gas, a halogen-containing gas and an oxygen-containing gas, wherein the flow rate of the element-containing gas and the oxygen-containing gas is approximately 1 0 0 sccm or lower; Pass a power supply of about 1,000 watts or lower to the coil in the processing chamber to produce 33 200401946 to generate a plasma; introduce a first containing at least a halogen-containing gas and an oxygen-containing gas Two process gases, wherein the flow rate of the i-containing gas and the oxygen-containing gas is at least 3 5 Osccm; a power source of about 1,000 watts or less is passed to a coil provided in the processing chamber to maintain a plasma Applying a bias power higher than about 5 watts to the support element; and etching the exposed portion of the chrome-based photomask layer. 2 6. The method according to item 26 of the scope of patent application, wherein the second process gas has an oxygen-containing gas with a first-rate rate between 150 sccm and 400 sccm, wherein the oxygen-containing system is composed of oxygen, carbon monoxide, carbon dioxide, and combinations thereof. Selected from the group. 27. The method according to item 26 of the scope of patent application, wherein the second process gas has an element-containing gas having a first-rate ratio between about 200 sccm and 600 sccm, wherein the halogen-containing gas contains at least one of chlorine, carbon tetrachloride Selected from the group consisting of hydrochloric acid, hydrochloric acid, and combinations thereof. 28. The method according to item 26 of the scope of patent application, wherein the flow rate of the second process gas is between about 350 sccm and about 1000 sccm, and wherein the flow rate of the oxygen-containing gas is between about 150 sccm and 400 sccm, and the The flow rate of the halogen-containing gas is between about 200 sccm and 600 sccm. 34 200401946 2 9. The method according to item 26 of the scope of application for a patent, wherein the molar ratio of the halogen-containing gas to the oxygen-containing gas in the second process gas is between about 1: 1.5 and about 4: Between 1. 30. The method according to item 26 of the scope of patent application, wherein the second process gas further comprises an inert gas selected from the group consisting of helium, argon, xenon, neon, krypton, and combinations thereof. 3 1. The method according to item 26 of the scope of patent application, wherein the plasma is maintained in a step which includes at least maintaining the pressure of the processing chamber between about 2 mTorr and about 50 mTorr. The reticle is maintained at a temperature between about 50 ° C and about 150 ° C. An RF power source of about 300 watts and about 1,000 watts is applied to a coil in the processing chamber to generate a plasma, And apply a bias power source between about 20 watts and about 40 watts. 35