TWI338921B - Improved method for etching photolithographic substrates - Google Patents

Description

1338921 IX. Description of the Invention: TECHNICAL FIELD OF THE INVENTION The present invention relates generally to semiconductor processing, and more particularly to an improved method of etching a etched substrate. [Prior Art] In order to improve device performance, the density of semiconductor circuits is continuously increasing. The increase in circuit density is achieved by reducing the feature size. Current technology

The feature size of 〇·15 μm and 〇.13 μm is targeted, and it is expected to be further reduced in the near future. The precise dimensions of the features within the device are controlled by all steps in the manufacturing process. The vertical dimension is controlled by the doping method and the layering method. The horizontal dimension is mainly determined by photolithography. The horizontal width of the lines and spaces that are formed into a circuit pattern is often referred to as the critical dimension (CD).

Photolithography is a technique used to form precise circuit patterns on the surface of a substrate. These patterns will be transferred to the wafer structure by subsequent etching or deposition. Ideally, the print step produces a pattern that precisely matches the design size (correct CD) at the desired location (so-called alignment or calibration). The method of multiple steps in the name of the printing process. In this method, the desired pattern is first formed on the reticle; then, the operation of the reticle is used to transfer the pattern to the substrate, which is transmitted through the patterned reticle. The radiation body, such as ultraviolet light (UV), exposes the radiation-sensitive coating on the substrate. When exposed to the radiation, the coating (photoresist) undergoes a chemical change that renders the exposed regions more or less soluble in subsequent developing chemicals. The Department of Light (4) technology is well known in the art, and its general knowledge can be found in the article "Introduction to Microlithography" by Thompson et al., edited 1339821. Thus, the reticle plays a dominant role in generating circuit patterns on many substrates, so Any defects introduced during the manufacture of the reticle will be replicated on all wafers imaged by the reticle. Therefore, for high-capacity manufacturing methods, high-quality reticle that reliably represents the design pattern and size is produced. There are two main types of masks that are well known in the art: absorbing reticle and phase shifting reticle. Typically, the absorbing reticle is optically coated with an opaque film such as Cr. The transparent substrate (for example, fused quartz, CaF^, etc.) may comprise a single layer or multiple materials (for example, an anti-reflective layer (AR chrome) on top of the lower chrome layer). In the binary chrome mask In the case, generally used opaque films include, but are not limited to, (listed under the trade name): AR8, NTAR7, NTAR5, TF11 and TF21. This opacity is produced during the manufacture of the reticle. The film is deposited on a transparent substrate; then, a photoresist layer is deposited on top of the opaque layer and patterned (eg, exposed to a laser or electron beam). Once exposed, the photoresist layer is subsequently developed to expose the layer to be removed. Subsequent opaque film regions' and subsequent etching operations remove the exposed film to form an absorbing reticle. There are two well-known subtypes of phase shifting reticle in the art: parent k-type reticle and embedding A light-reducing reticle. Typically, an alternating phase-shifting reticle is constructed of an optically transparent substrate (eg, condensed quartz, Cab, etc.) coated with an opaque film (eg, Cr and anti-reflective Cr). During the manufacture of the cover, an opaque film is deposited on the transparent substrate; then, a photoresist layer is deposited on top of the opaque layer and patterned using a laser or electron beam. After exposure to a 6 1338921, the photoresist is subsequently developed. The layer exposes the area of the underlying opaque film that is to be removed. The etching process removes the exposed opaque film to expose the underlying substrate. A second process is used to etch the precise depth into the underlying substrate. Alternatively, as is well known in the art, the substrate can be subjected to a second photoresist coating and development process prior to the second etching process. Embedded Attenuation Phase Shift Mask (EAPSM) The ground system consists of an optically transparent substrate (eg, fused quartz, CaF2, etc.) coated with a film or film stack that is attenuated by 180° degrees of light transmitted at the wavelength of interest, and then an opaque film or film stack is deposited. (eg, Cr and anti-reflective Cr) on the phase shifting material. Next, a resist layer is deposited on top of the opaque layer and patterned (eg, using a laser or electron beam). Once exposed, the light is subsequently developed. a resist layer to expose the underlying opaque film to be removed; then, using a surname process to remove the exposed opaque film, and exposing the underlying phase shift/attenuation film or film stack β after etching the opaque film, using The second etching process is performed by sequentially shifting the layer and stopping on the lower substrate. Selectively, the etch stop layer may exist between the phase shift layer and the substrate. In this case, the second surrogate process will selectively stop Etching blocking layer. Ideally, the etching process will have a high etch selectivity with respect to the topmost etch stop mask (eg, photoresist, electron beam stop, etc.) as follows (substrate or etch blocker), resulting in a smooth The upright sidewalls feature to accurately replicate the CD of the original mask (e.g., photoresist) pattern. Wet etching methods (such as aqueous solutions of argon acid and ammonium nitrate lanthanum for AR Cr/Cr etching) show good etch selectivity to the etch mask and the underlying substrate, but are uniform, and cause serious masking. Lateral erosion, as well as the creation of a special 1338821 sign with a slope. Touching the characteristic profile with the slope on the side changes the characteristic CD of the etch, and undesired changes in the CD and/or characteristic contours having a slope will degrade the optical performance of the finished reticle. The dry etch (plasma) process is another well known alternative to wet etch. The plasma etching method provides an etching result that is superior to the anisotropic method of the wet etching method. Dry lithography is generally used in the manufacture of all three mask types. In the case of a binary Cr mask, a mixture of a gas-containing gas and an oxygen-containing gas is typically used, and an additional gas-containing component containing an inert substance and a passivation is used to improve process performance. Early dry etching operations on reticles used low-density (about 1 09 ions/cm 3 ) plasma in an electric stalk-type (two-pole Zhao) reactor, while the most advanced dry-etch reticle method used high density ( 101. to 10) 2 ions / cubic centimeter) configuration (such as inductively coupled plasma (ICP), transformer coupled electric shock (TCp), electron cyclotron resonance (ECR), etc.). For an example of a dry remnant method for a binary Cr reticle, the method typically comprises three main steps Φ. The first step utilizes a gas-containing plasma (eg, c丨2, HCl, CC14, BCI3) to remove the anti-reflective coating (eg, chromium oxide, chromium nitride, - nitrogen oxide). Optionally, the AR Cr|i step may include an oxygen-containing gas (eg, 〇2, CO, c〇2, n2〇, n〇2, s〇2, etc.) and an inert gas (eg, He, Ar, Ne) , Xe, Kr, etc.). This first step can be performed on a time basis or terminated by the end point technique (e.g., laser reflectance spectroscopy, luminescence spectroscopy) at the AR Cr/Cr interface. The second step etches the Cr host material to stop on the underlying film or substrate. The process gas mixture used in the second step typically comprises a source of gas and a source of oxygen. 8 1338921 ', the first step is the same, the process gas mixture can also have the same treatment as the first step and the second step: Γ l land, the second step can be terminated by the use of the end point technology. condition. The third step is to use the surname step to make the rhyme complete G load zone. This (four) engraving step can also be used to improve the profile with a slope that is encountered at low heart =. Although the longer time for money can be:: = Full clearance of high-density Cr areas and ensuring improved (more upright) characteristics

The over-synchronization time of = will also result in greater lateral money and higher deviations. The parameters of the (four) step can be the same as the first and second steps: any - (or both). Typically, the time of the surname step is based on the ratio of the time of the previous step. The slag removal or trimming step can be performed prior to etching the AR chrome layer to improve the profile of the surname mask (e.g., photoresist). Although the plasma lithography method is more anisotropic than the wet button scribe method, the electric incineration method can still cause dimensional changes in the patterned material. The degree of increase or decrease on the CD caused during the process of (4) is called "CD deviation." The CD deviation during the etching process can be obtained by taking the final feature cd after the etching process and subtracting the original feature CD before the etching process. It is expected that the degree of lateral etching that causes CD bias can be minimized. In the case where the CD deviation of the process is non-zero, the CD deviation uniformity must be considered. The CD deviation uniformity is at the average cD. The distribution of values around the deviation value. The CD deviation uniformity can have both systematic and random components. It has been observed in reticle characterization that the non-uniformity of the system corresponds to local etch loading effects (eg microloading) Or load effect) 9 1338921 Generally referred to as "load dependence," the phenomenon is known in the art of dry etching. Load dependence refers to the relationship between the area of the material to be etched and the material characterization rate. For example, in the binary Cr mask dry scribe method, the vertical Cr surname rate will become lower in regions with higher cr density. Assuming that the lateral etch rate is also load dependent, it is reasonably desirable that the 岔 more Cr 将 will have a lower lateral etch rate and thus a lower CD bias. However, what is actually observed is the opposite, that is, higher when compared to the lower Cr density (lower load) zone.

Cr density characteristics (having a lower vertical etch rate) typically have higher CD bias. * :, ', to evaluate the CD performance of the process, it is necessary to consider two factors: the lateral velocity of the Cr stack, and the last veranda of the characteristics of the touch. In the case of a Cr-like pattern in which the pattern contains different Cr-loading regions, the higher & density (high photoresist density or headroom) region typically characterizes a low surname rate (as 所θ^ light day) ... is a larger CD deviation (unexpectedly) when compared to a low load area. Therefore, it is necessary to provide a method for improving the characteristic profile and CD performance. The present invention does not provide the advantages associated with the present invention. Accordingly, it is an object of the present invention to provide a method of performing the prior art, which is an improvement of the art. A further object of the present invention is to provide a method for processing a photo-etching substrate 10 1338921 comprising: loading the photo-etching substrate into a vacuum chamber; and cooling the photo-etching substrate to a target temperature; introducing at least one process gas into the vacuum chamber; after the cooling step, igniting a plasma from the process gas; using the plasma to treat the photoetching substrate; And discharging the photo-etching substrate from the vacuum chamber. A further object of the present invention is to provide a method for processing a photo-etching substrate, comprising: loading the photo-etching substrate onto a substrate holder in a vacuum chamber; a fluid to control the temperature of the photo-etching substrate; introducing at least one processing gas into the vacuum chamber; igniting-electropolymerizing from the processing gas; using the plasma to treat the photo-etching substrate; and from the vacuum chamber Unloading the photo-printing substrate. A further object of the present invention is to provide a method for printing a substrate with a surname, comprising: loading the photo-etching substrate onto a substrate holder in a vacuum chamber; introducing at least one processing gas into the substrate Having ignited a first plasma from the process gas; for the first set of method conditions, using the first electrode to etch the substrate; cooling the etch substrate to a target ρ After the cooling step, igniting a second electrical combustion from the processing gas; using the second plasma to etch the lithographic substrate substrate for a second set of method conditions; The vacuum chamber unloads the photo-etching substrate. Still another object of the present invention is to provide a method for controlling substrate temperature by a thermal mass during a plasma process, comprising: adjusting a temperature of the substrate to a target temperature; loading the Substrate to a substrate support in a vacuum chamber: upper; introducing at least one process gas into the vacuum chamber; igniting an electropolymer from the process gas; using the plasma to treat the substrate; and from the vacuum 11 ^ 38921 The invention further provides a method for etching a photo-etching substrate, comprising: loading the photo-etching substrate onto a substrate holder in a vacuum chamber; introducing at least a processing gas into the vacuum chamber Internally; from the process gas igniting - plasma, 'in a first set of method conditions, the plasma is etched to etch the substrate at the -target temperature; in the second method of conditional use Discharging the photolithographic substrate at a second target temperature; and unloading the photolithographic substrate from the vacuum chamber.

A number of related objects of the present invention have been described above, and such objects are to be read as merely depicting a number of more prominent features and applications of the π intended invention. A number of other beneficial results can be obtained by applying the invention in a different manner, or by modifying the invention within the scope of the disclosure. Therefore, the other objects and the complete description of the present invention can be understood by referring to the detailed description of the present invention and the preferred embodiments of the present invention in addition to the invention obtained in conjunction with the accompanying drawings. Come and get it. In order to summarize the present invention, the invention includes an improved method of using a plasma system to etch a substrate. A feature of the present invention is to provide a method for processing a photolithographic substrate such as a binary Cr mask or an attenuated phase shift mask on a base support in a vacuum chamber. The method includes using plasma in a vacuum chamber. Prior to processing, for example, etching the etched substrate, the etched substrate is cooled to a target temperature, such as less than about minus 3 degrees Celsius. The etch of the etched substrate is generated in a vacuum chamber that processes the photo-printing substrate or in a separate chamber that does not have to be in a vacuum. Introducing at least 12 1338921, for example, a gas-containing gas and an oxygen-containing gas, into a vacuum chamber. The gas-containing gas can be introduced in a larger ratio than the oxygen-containing gas ratio of about 15 t匕1. After the photo-touch substrate reaches the target temperature, the plasma is ignited from the process gas, wherein the photo-printing substrate is processed using the plasma. In addition, the processing of the optical printing substrate can be modulated on a time basis, such as amplitude modulation or pulse modulation. Once the ί is completed, the photonic substrate can be unloaded from the vacuum chamber. Another feature of the present invention is to provide a method for processing, for example, a binary Cr mask or an optically imprinted substrate that is embedded in a fading phase shift mask. The method includes controlling the temperature of the optical printing substrate through a fluid such as an inert gas at a pressure of less than about i Torr during the process of, for example, etching of the optical residual substrate in the vacuum chamber. The fluid temperature can be controlled and the body can flow continuously through the vacuum chamber. Additionally, at least one of the chamber surfaces of the vacuum chamber can be temperature controlled wherein the chamber surface can be positioned about 5 cm from the surface of the photolithographic substrate. Right-hand 畲 令 令 基板 基板 在 在 在 在 在 在 在 在 在 在 在 在 基板 基板 基板 基板 基板 基板 基板 基板 基板 基板 基板 基板 基板 基板 基板 基板 基板 基板 基板 基板 基板 基板 基板 基板 基板 基板Once the process is complete, the photo-printing substrate can be unloaded from the vacuum chamber. Yet another feature of the present invention is to provide a method of engraving a substrate, such as a C4 cover, in a vacuum chamber, the method comprising the step of introducing at least: a process gas into the vacuum chamber. The first set of process conditions can be designed to etch the screen printed substrate by igniting the first plasma from the process gas and then using the first electropolymer to process the first set of process conditions. Anti-reflective layer. Further, the photoresist layer of the substrate on which the light is removed can be removed from the < in

J 13 1338921 The etched substrate is cooled to the target temperature prior to any further processing of the photolithographic substrate. Cooling of the etched substrate can occur in the vacuum to process the etched substrate or in a separate chamber that does not have to be under vacuum. Once the target temperature of the photolithographic substrate is obtained, the first plasma is ignited from the process gas and the first set of process conditions are utilized to quantify the photolithographic substrate. Once the process is complete, the photolithographic substrate can be unloaded from the vacuum chamber. Still another feature of the present invention is to provide a method of controlling the temperature of a substrate with a high thermal mass during a plasma process, the method comprising the step of adjusting the temperature of the substrate on the substrate holder in the vacuum chamber to a target temperature. At least one process gas is introduced into the vacuum chamber. The plasma is ignited from the process gas, wherein the substrate is processed using the electrical destruction. The substrate can be thermally isolated from the substrate holder. In addition, the plasma process can be designed to introduce less than 5 watts per square centimeter of power into the substrate. Once the process is complete, the substrate can be unloaded from the vacuum chamber. Yet another feature of the present invention is to provide a method for processing a photoetching substrate such as a binary Cr mask or a MoSi〇N phase shifting mask on a substrate holder in a vacuum chamber, the method comprising introducing at least one processing gas into the The steps in the vacuum chamber. The plasma is ignited from the process gas, wherein the photolithographic substrate is etched using the plasma at a first set of process conditions at a first target temperature. The etched substrate is then applied to the second target temperature using the electropolymer in a second set of process conditions (4). The second target temperature may be higher or lower than the first target temperature depending on the material to be etched from the photolithographic substrate. Cooling or heating of the etched substrate can occur in a vacuum chamber that processes the etched substrate 1^38921 or in a separate chamber that does not have to be under vacuum. In addition, & the first set of process conditions can be designed to etch the anti-reflective layer of the photo-etching substrate, and can be stripped on the photo-printing substrate before any residual Cr on the remaining photo-printing substrate Photoresist layer. Alternatively, the first set of process conditions can be designed to name the M〇SjON layer of the MoSiON phase shift mask, and the etching can be stopped at the interface of the MoSiON layer relative to the surface of the M〇Si〇N phase shift mask. . Once the process is complete, the photolithographic substrate can be unloaded from the vacuum chamber. In order to provide a better understanding of the following detailed description of the invention, the present invention has been more broadly described in the foregoing. Additional features of the invention will be described hereinafter which form the subject of the scope of the invention. In addition, it should be understood by those skilled in the art that these equivalents are not to be construed as a departure from the spirit and scope of the invention. [Embodiment] The viewpoint of the present invention will be described by referring to an inductively coupled plasma chamber. A suitable #刻室 contains the Mask Euher IV platform sold by Oerlikon, Inc. of St. Petersburg, Florida. Other reactor configurations can be used to perform the methods of the present invention, including capacitively coupled reactors (eg, reactive ion etchers (RIE) 'plasma enhanced (pE) reactors, diode reactors, etc.), high density reactions (eg, lCp, Tcp, etc.) and magnetically enhanced reactors (eg, ECR, magnetically enhanced reactive ion etcher (MERIE), etc.). Figure 1 is a schematic representation of an ICP reactor. The process gas is introduced into the chamber 15 through the gas inlet 120. The flow of the process gas mixture is roughly 15 1338921 regulated by a mass flow controller (not shown). The processing chamber 15 includes a wall 〇〇 and an energy-transmissive chamber surface i 10 . The chamber walls 1 are typically metal (e.g., aluminum, stainless steel, etc.) and the energy transparent surface 110 is typically dielectric (e.g., ceramic). The plasma zone 145 is defined by the chamber wall 100, the substrate support 135, and the energy transparent surface 110. The RF energy from the RF generator 115 is supplied to the inductor 105. The RF energy from the generator i 15 can be modulated by time (e.g., amplitude, frequency, etc.). The RF energy is coupled to the energy through the energy transparent surface 110. Slurry area 145. An impedance matching network (not shown) enables RF energy from the RF generator 115 to be efficiently transferred to the plasma 145 °. The substrate support is disposed in the chamber to support the etched substrate during the process. The substrate holder 135 is connected to the power supply 1400. In the case of a voltage-based RF voltage supplied to the substrate holder, an impedance matching network (not shown) is interposed between the bias supply 140 and the substrate holder 1 35. The RF bias can be voltage controlled or power controlled. The bias supply 140 can be modulated by time (eg, amplitude, frequency, etc.). In conventional dry etching, the temperature of the substrate is actively maintained by maintaining the substrate in thermal contact with the shipboard substrate support. control. This is typically accomplished by the art known as rear slewing cooling. This can be performed by mechanically or electrostatically clamping the substrate to the substrate holder. In the case of the mechanical clamping method, the lost body physically contacts the side or top surface of the substrate to maintain the substrate in contact with the substrate holder. Once held, a gas (e.g., helium) is introduced into the space between the substrate holder and the wafer to increase the heat transfer between the substrate and the substrate holder of the base 13 1338921. In order to achieve active substrate temperature control, the gas pressure between the wafer and the substrate holder is typically higher than 3 Torr. Alternatively, the substrate can be electrostatically clamped to the substrate holder with the same rear gas introduction. Although the electrostatic clamping method only contacts the back surface of the substrate, it is difficult to electrostatically clamp the dielectric material. Currently, the reticle substrate is dielectric. If the electrostatic clamping voltage is sufficiently high, the conductive layer or semiconductor layer disposed on the top of the substrate can be clamped "through the substrate". Due to the defect sensitivity of the optical printing substrate, the permissible contact with the reticle substrate has historically been limited to the outermost 1 mm of the rear of the substrate. This additional substrate contact limitation has prevented the clamping of the etched substrate during the dry etch process. Note that due to the quality of a typical photolithographic substrate, a heat transfer gas can be introduced between the substrate and the cathode at low pressure without clamping (less than about 1 Torr for a 150 mm reticle substrate). While the low pressure gas will provide limited heat transfer to the substrate, gas pressures less than the 丨 Torr are typically not sufficient to actively temperature control the substrate, and therefore, the temperature of the reticle substrate will rise during exposure to the plasma. 2 shows that the substrate 130 is optionally disposed over the stent cover plate 2〇5, which may be in thermal or thermal isolation from the substrate support 135. " Xuan bracket cover plate 205 is placed on the substrate holder 135. Typically, the cover sheet contains recesses adapted to the substrate 130 such that the substrate is substantially coplanar with the top surface of the cover sheet. The cover plate contacts the mask only on the outer edge of the back surface of the mask 2丨5. The contact area on the back side of the reticle is typically within 1 mm of the outermost surface of the back surface of the reticle. The contact between the reticle and the cover sheet can be a continuous scaffolding, point contact, or some combination thereof. Since 17 1338921 is the cover plate 205 which only contacts the outer edge of the back surface of the photomask 13A, there is a thin gap 21〇 between the back surface of the substrate 130 and the substrate holder 135. Although the temperature of the substrate holder is controlled during contact with the heat transfer fluid (not shown) during the process, there is only limited heat transfer between the substrate 13A and the cover sheet 2〇5. Therefore, in the absence of rear helium cooling, the photolithographic substrate will be heated by the plasma during the dry etching process. The heating rate during the process is a function of the process parameters, the process parameters include #RF power, chamber wall temperature, and the like. The etched substrate is typically not actively cooled during the dry etch process. Therefore, the temperature of the substrate will increase during exposure to the plasma. For a typical ICP dry etch process for a photolithographic substrate, the thermal load at the substrate will be less than about 0.5 watts per square centimeter. Due to the relatively high thermal mass of the photolithographic substrate, dry etching without active cooling will result in minimal temperature rise during processing (typically less than about 2 〇 c / min). For a typical plasma process used to etch a photo-etched substrate, the total temperature rise will be less than about cut. . . A 'selective ground' diffusion barrier (not shown) can be placed on the cover to improve the uniformity of the process. The process gas and reaction products are removed from the chamber through a vacuum outlet 125. A throttle valve (not shown) is disposed in the outlet to control the chamber pressure during the dry etching process. Figure 3 shows a block diagram of the method flow. The method begins with a photolithographic substrate having a film to be dry etched. The etch stop mask is deposited on the substrate and patterned by methods well known in the art; 18 1338921 The substrate is then cooled to a temperature of less than about -30 °C. Once cooled, the substrate is subjected to a plasma process to remove the material left behind by the etch stop mask. Alternatively, once the dry etch process is completed, the substrate can be heated to about 20 ° C before the substrate is exposed to atmospheric conditions. Heating the substrate prior to exposure to the atmosphere prevents condensation that can adversely affect the performance of the mask. This heating step can be performed in a plasma reaction chamber. The plasma heating step may consist of a reactive gas mixture (e.g., an oxygen-containing gas that removes residual etching photoresist) or a non-reactive gas (e.g., He, Ar, etc.). The cooling step before the # inscription can occur in the plasma etching chamber or in the separate chamber. During the cooling process, the chamber can be maintained at a pressure greater than or close to atmospheric pressure or at a pressure less than atmospheric pressure. In all cases, the atmosphere should be clean and dry to prevent defects from foreign matter or condensation from forming on the board. In the case where the substrate is not sufficiently cooled to maintain a sufficiently low temperature in the etching process, the process may be separated into multiple segments (eg, stopping the etching and cooling the substrate before the repetitive etching process) Repeated many times. During the use of more than one method step (such as binary etch reticle), the substrate temperature can be cooled between the various steps of the process. Recall that in the electricity (four) process, because there is no active cooling of the substrate : Therefore, the base m will increase the force during the process of the plasma processing step. In the case where the substrate is heated between steps, it is possible to use a non-reactive plasma to heat the substrate 0 1338921 and has observed Yes, when the temperature is less than about _9 (rc, the selectivity of Cr: Ar Cr increases. At -40 ° C, the etching selectivity cr : AR Cr is about 1.1 ° and at about -140 ° C A similar process will result in a Cr:AR Cr etch selectivity of approximately 3:1. Based on these observations, the AR chrome layer can be used as an underlying chrome etch mask at low substrate temperatures. - Figures 4a through 4d Show typical light Schematic of the etching process. In the case of a light-masked binary Cr mask, Figure 4a shows an example of a masking junction before etching. The structure comprises an optically transparent substrate 415, which can be broadly defined For inclusion, but not limited to, a material that is transparent to wavelengths of light of 3 nanometers or less (eg, 248 nm, 193 nm, 57 nm). The opaque layer 410 is disposed on a substrate 415, which may be metal (eg, a network) or The other anti-reflective (AR) layer 405 is disposed on the opaque layer 410, and the AR layer 405 is forbearing to improve the photo-printing performance of the mask. The ar layer may be composed of a metal derivative ( For example, metal oxides, metal nitrides, metal carbides, metal oxynitrides, etc.) Layer 400 represents an etch stop mask that can pattern the underlying opaque layer and the AR layer, which can be based on a polymer ( For example, a photoresist or an electron beam resist) or a hard mask material (for example, SiO 2 , SiN, DLC, etc.) patterned in the previous method step. FIG. 4b depicts an etching step of removing the AR cladding layer 405. aR layer In the case of a network containing a gas-based etching method, the flow rate of the gas-containing gas is typically in the range of about 5 〇 sccm to about 4 〇〇 seem. Alternatively, the AR layer etching method can be used. Containing an oxygen-containing treatment gas 'where the oxygen-containing gas accounts for 〇% to about 5% of the total gas stream. The inert gas 13 1338921 gas may also be present in the process gas mixture, which typically constitutes 〇% and about 20%. The total airflow between %. In the ICP configuration, the power supply power in the | AR buttoning step is typically between approximately 100 watts and approximately 1000 watts. The RF bias power is approximately 1 watt and approximately 30 watts. between. The RF bias supply can be voltage controlled. The treatment pressure is typically between about i millitor and about 2 Torr. Figure 4e shows the step (4) of removing the opaque layer 41() and the over-etching step. In the case where the opaque layer is a chromium-containing film, a gas-containing and oxygen-containing etching method is used. Typically, the gas-containing gas flows between about 5 〇 coffee and about 400 seem, and the oxygen-containing gas constitutes about 2 〇 / of the total gas stream. It is about 50%. An inert gas may also be present in the process gas mixture, and the inert gas typically constitutes a total gas stream between 0% and about 2%. The method parameters can be the same as the opaque layer surname step, or can be different. For example, during the over-etching step of the opaque layer, it is not uncommon to increase the composition of oxygen to improve the feature profile. ” #4d is a schematic diagram showing the typical reticle lithography of the step of removing the photoresist layer _. In the ICP configuration, the power of the power supply in the opaque layer is stepped in the form of a large tile and approximately The QRF bias power between the tiles is between about 1 watt and about 30 watts. The RF bias supply can be voltage controlled. The processing pressure is typically between about 丨 Torr and about 20. However, it is not practical to clamp and cool the conventional substrate at a temperature lower than room temperature during the electropolymerization process. Due to the control limitation, it is not practical to use the 13 1338921 substrate for rear cooling. Compared with the conventional substrate, the optical printing substrate has a relatively high thermal quality (for example, about 22 H/K of a 6-inch square dazzling quartz photomask substrate and about 17 J/K of a 6-inch wafer). The thermal mass of the etched substrate can be cooled during the method by cooling the substrate before the button is engraved without actively cooling the substrate. Due to the high thermal mass of the substrate, relatively low RF power, and short Process time, the temperature of the etched substrate The temperature from the beginning of the process typically rises only less than about 4%, and during the period of plasma turning on, the substrate temperature will increase monotonically. Figures 5a and 5c show at room temperature (2〇.〇) Prior art examples of Cl2/〇2 dry etch results in low Cr density patterns. Both examples show severe bevels that are detrimental to the optical properties of the reticle in the etched feature profile, which the inventors have discovered. Yes, lowering the substrate temperature will violently change the etched Cr profile. Figures 5b and 5d show examples of Ci2/〇2 dry etch results in low Cr density patterns at substrate temperatures of -9 °C. It is 'in Figure 5b' that the etching profile has been substantially improved; and in the 5th figure, the positive slope has been replaced by a negative side etching profile. Although the above description has described the application of the present invention to etching two light Chrome reticle, but it is also perceptible that the present invention is also applicable to dry etch processes on other lithographic substrates such as EAPSM and alternate aperture PSM masks. It is well known in the art that EASPM light Fluorine-containing plasma used in the manufacture of the cover To etch molybdenum molybdenum (Mosi) and molybdenum oxynitride (MoSixNyOz) films. During the manufacture of EAPSM masks, it is expected that 22 1338921 achieves high etch selectivity between the phase shifting material and the underlying substrate. To get this selectivity, use a lower ion energy method (reducing the applied RF bias). However, while reducing the RF bias improves selectivity, it also sacrifices etch anisotropy, ie, reduces The RF bias causes a more uniform feature rim. Cooling the etched substrate before the remainder provides improved etch anisotropy at low RF bias power. Example experiments were performed in St. Petersburg, Florida. The commercial Mask Etcher IV system sold by the US 〇erHk〇n company. Among the binary Cr mask etchings, in addition to ensuring the transfer of high-fax patterns from photoresist to Cr, it is expected to obtain high selectivity to photoresist. When the substrate is at room temperature, the method conditions for obtaining a higher Icp power (>200 watts) of Cr: photoresist selectivity > 2:1 and lower oxygen concentrations often result in non-erectal & contours and/or Bad pattern transfer fax. This previously unimplemented method space can become useful when the substrate is cooled to a lower temperature. In an experiment, the Oerlikon Mask Etcher IV was used to name four masks. The first two masks (masks 2983 and 2982) were etched at room temperature using two different etching processes. Mask ID mask 298.3 Mask 2982 Method "room temperature / low 〇 2" "room temperature / moderate 〇 2" Cl2 195 seem 180 seem 〇 2 5 seem 20 seem Pressure 4.5 mT 4.5 mT RIE 800 Vpp 800 Vpp 23 1338921 600 Watt 218+109 seconds 3.0 ICP 600 watts time (last name + past name engraved) 484 + 242 seconds selectivity 2./ (Note: This: the mask is the rice to the end point (for example, by the laser: the end point method The decision) 'then use the same method of the large 呔N to do 50 〇 /. Over-etching.) Mask 29 84 and 2981 oil 啻 will be cooled to about -90 C before the red etch. The masks cooled in the 戎 method module _ ψ, 秘, 人一一 etch the mask ID method using the same method conditions used on the room temperature mask. Method Cl2 〇2 Pressure RIE ICP Time (etch + over etch) Selective mask 2981 1 low temperature / moderate Ο: 180 seem 20 seem 4.5 mT 800 Vpp 600 watt 268 + 134 seconds 2.9 mask 2984 'low temperature / low 〇 2, 195 seem 5 seem 4.5 mT 800 Vpp 600 watt 466 + 233 The second 3.3 mark rate varies depending on the temperature and oxygen concentration. Under low oxygen conditions, the etch rate is about 4% faster at low temperatures; under high oxygen conditions, the etch rate is 23% slower. The selectivity to the photoresist is approximately the same as the temperature in the high oxygen conditions. At low oxygen 4, when operating at low temperatures, the selectivity is significantly better. A closer examination of the photoresist, the ARC layer, and the Cr' body layer's engraving rate shows that the selectivity between the layers also varies with temperature and oxygen concentration. Figure 5 shows the Cr wheel gallery etched by each mask. It is understood from these corridors 24 1338921 that both oxygen and initial substrate temperatures have a substantial effect on the profile. Low temperature experiments tend to show a more upright or undercut profile, while room temperature experiments tend to show a more beveled profile. Oxygen plays a role in the tendency to be beveled (or less undercut) in hypoxic experiments than in hyperoxic experiments. The disclosure of the present invention includes the scope of the patent application of the appendix and the contents contained in the above description. Although the present invention has been described in terms of a particular form of particularity, the present invention is disclosed by way of example only, and the details of the structure and the ' Without departing from the spirit and scope of the invention. The invention has now been described. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view of a typical ICP plasma system; Fig. 2 is a schematic view of a substrate holder; Fig. 3 is a block diagram of the method flow of the present invention; Schematic diagram of the engraving process, showing the mask structure before the engraving; Figure 4b is a schematic diagram of a typical mask surname process, showing the engraving step of removing the ar cladding; Figure 4C is a schematic diagram of the mask (process) The etching step of removing the opaque layer is shown; the 4th drawing is a schematic diagram of a typical reticle engraving process, showing the step of removing the photoresist layer; the 5a drawing is an electronic photo/sm+, , ^ is not used Prior art etching results; 25 1338921 Figure 5b is a scanning electronic photograph showing the etching results using the present invention; Figure 5c is a scanning electronic photograph showing the etching results using the prior art; and Figure 5d is a scanning electronic photograph showing the use The etching result of the present invention. In the drawings, like reference characters refer to the like. [Main component symbol description] 100 chamber wall 105 inductor 110 energy transparent chamber surface 1 15 RF generator 120 gas inlet 125 vacuum outlet 130 photo-etching substrate 135 substrate holder 140 bias supply 145 plasma area 150 chamber 205 bracket cover Plate 210 gap 215 photomask 400 layer (etch stop mask 26 1338921 405 anti-reflection (AR) layer 410 opaque layer 415 substrate

27

Claims (1)

1338921 X. Applying for a patent garden: 1. A method for processing an opaque film of a photo-etching substrate comprises: loading the photo-etching substrate into a vacuum chamber; cooling and printing the substrate to a target temperature, The light print substrate is not actively clamped during the cooling step; at least - the process gas is introduced into the vacuum chamber; after the /, the step, a plasma is ignited from the process gas; The optical printing substrate is processed, the optical axis printing substrate is not actively cooled during the processing step; and the vacuum printing substrate is unloaded from the σH vacuum. 2. If the patent application scope is the first binary Cr mask. The method of the member is to first print the substrate system. As in the method of claim 1, the target temperature is in the range of less than about thirty degrees Celsius. 2. The method of claim 1, wherein the optical residual substrate is phase-shifted. Bauxite is very good for you. 5. If you apply for the fourth method of patent scope, enter the attenuated phase shift mask. , the method ', the phase shifting reticle is embedded 6. As in the patent application scope, the method is engraved. The method of claim 6 is the method of claim 6, wherein the process step comprises a gas containing gas and an oxygen-containing gas. The method of claim 7, wherein the milk-containing system introduces the vacuum chamber and the crucible 28 1338921 at a ratio of greater than about 15 fcl. 9. The method of claim 1 is as follows. Further, the process of modulating the optical residual printed substrate on a time basis is included. 10. The method of claim 9, wherein the modulation is amplitude modulated. 1 1. The method of claim 9, wherein the modulation is pulse wave modulation. 12. A method for processing an opaque film of a photo-etching substrate, comprising: loading the photo-etching substrate onto a substrate holder within a vacuum chamber; controlling a temperature of the photo-etching substrate through a fluid, The photo-etching substrate is not actively clamped during the control temperature step; introducing at least one processing gas into the vacuum chamber; igniting an electric combustion from the processing gas; <# t μ光I Insulin substrate, the light shoe substrate is not actively cooled during the processing step; and the photolithography substrate is unloaded from the vacuum chamber. 13. The method of the first step of the patent application, comprising at least a method of at least mu, wherein the substrate holder uses M to support the photo-etching substrate. 14. If applying for a patent scope body. The method of claim 1, wherein the flow system is a gas 15. The method of claim 14 is wherein the gas system is inert. 16. The method of applying the patent range of 15 is further white. About 1 tor (T〇 Rr) - gas $ quasi-holding small hole body Fortification within the vacuum chamber. 17. The method of claim 29, wherein the fluid continuously flows through the vacuum chamber 1338921. 1 8. If the scope of the patent application is 筮1 7 tS W, the method of the 7th item, where the temperature of the flow system is controlled. 1 9. If the scope of the patent application is 笸], J is the method of item 12, wherein at least one of the chamber surfaces is temperature controlled. 2 0. If the application for patent Fan Yuan 坌 摩 has the method of item 19, wherein the surface of the chamber is positioned 5 cm away from the surface of the light substrate. 2 1. A method for printing an opaque film of a 4 earth plate, comprising: loading the photo-etched substrate to a straight substrate AA ^ with one of the substrate holders; introducing a v-process gas into the substrate Within the vacuum chamber; igniting the first plasma from the processing gas; for a first group of methods, you are born to use the first plasma to etch the photo-printing substrate; cooling the optical printing base 5 n" + standard temperature 'the photo-touch substrate is not actively sandwiched during the cooling step; Λ, P: after the 'ignition of the treatment gas - the second plasma; " Dijon-group method Condition, the second plasma is used to etch the etched substrate, and the stencil is not actively cooled during the etching step; and from the erection of the etched substrate. 2 2: The method of claim 2, wherein the cooling step occurs in a second chamber. The method of claim 2, wherein the cooling step occurs in the vacuum chamber. The method of claim 2, wherein the photolithographic substrate is a monolithic Cr mask. 25. The method of claim 24, wherein the anti-reflective layer of the photo-etching substrate is etched using the first set of methods of the first electropolymer. 26. The method of claim 25, further comprising stripping a photoresist layer prior to etching the Cr remaining on the photolithographic substrate. 27. The method of controlling the temperature of the photo-etching substrate by an amount of heat during the plasma process on the opaque film of the photo-etching substrate, comprising: adjusting a temperature of the photo-printing substrate to a target temperature, The optical printing substrate is not actively clamped during the adjusting temperature step; loading the photo-etching substrate onto one of the substrate holders in a vacuum chamber; introducing at least one processing gas into the vacuum chamber; from the processing gas Ignition of an electro-destructive substrate; the photo-etching substrate does not use the plasma to process the photo-etching substrate, actively cooling during the processing step; and from the vacuum to unloading the photo-fabric Printed substrate. 28. The method of claim 27, wherein the method is thermally isolated from the substrate holder. 29. The method of claim 27, wherein the plasma process heats a load into the lithographic substrate, as described in claim 27, wherein the plasma process is less than about 0.5 watts per square centimeter. XI. Schema: as the next page 31