TWI633811B - Plasma processing device and method for processing semiconductor substrate - Google Patents

Abstract

The invention provides a plasma processing device and a substrate manufacturing method, which include a reaction cavity, wherein at least a part of a top plate of the reaction cavity is an insulating material window made of an insulating material. The substrate supporting device is disposed below the insulating material window in the reaction chamber. A radio frequency power transmitting device is located above the insulating material window to transmit radio frequency power through the insulating material window and into the reaction cavity. A reaction gas injector is used to supply a reaction gas into the reaction chamber; a plurality of current carrier gas injectors are arranged below the reaction gas injector to inject a carrier gas of a certain flow rate into the reaction chamber. Adjusting the flow velocity of the carrier gas can effectively change the binding force of the carrier gas on the diffusion of the reaction gas, and then control the different distribution of the reaction gas in the reaction chamber to meet the needs of different processes.

Description

Plasma processing device and method for processing semiconductor substrate

The present invention relates to a semiconductor processing device, and more particularly to the technical field of uniform heating of a semiconductor processing device.

Semiconductor processing devices are well known in the prior art and are widely used in the manufacturing industries of semiconductor integrated circuits, flat panel displays, light emitting diodes (LEDs), solar cells, and the like. One type of plasma processing device is an important part of a semiconductor processing device. Generally, at least one radio frequency power source is applied in the plasma processing device to generate and maintain the plasma in the reaction chamber. Among them, there are many different ways to apply RF power, and the design of each different way will lead to different characteristics, such as efficiency, plasma dissociation, uniformity, and so on. One design is an inductively coupled (ICP) plasma cavity.

In an inductively coupled plasma processing chamber, the RF power source typically emits RF energy into the reaction chamber via a coiled antenna. In order to couple the RF power from the antenna into the reaction cavity, a window of insulating material is placed at the antenna. The reaction chamber can process various substrates, such as silicon substrates. The substrate is fixed on a chuck, and a plasma is generated above the substrate. Therefore, the antenna is placed above the top plate of the reactor such that the top plate of the reaction chamber is made of an insulating material or includes an insulating material window.

In the plasma processing chamber, various reaction gases are injected into the reaction chamber, so that chemical reactions and / or physical interactions between ions and the substrate can be used to form various characteristic structures on the substrate, such as etching, deposition and many more. In many process flows, an important index is the uniformity of processing inside the substrate. That is, a process flow acting on the center area of the substrate should be the same as or highly similar to the process flow acting on the edge area of the substrate. Therefore, for example, when the process flow is performed, the etching rate of the central area of the substrate should be the same as that of the edge area of the substrate.

Figure 1 shows a cross-sectional view of a conventional inductively coupled plasma reaction chamber design. The ICP reaction chamber 100 includes a substantially cylindrical metal side wall 105 and an insulating top plate 107, which constitute an air-tight space that can be evacuated by the evacuator 125. The base 110 supports a chuck 115 that supports a substrate 120 to be processed. Radio frequency power from the radio frequency power source 145 is applied to the coil-shaped antenna 140. The reaction gas from the gas source 150 is supplied into the reaction chamber through a line 155 to ignite and maintain the plasma, and thereby process the substrate 120. In a standard inductively coupled reaction chamber, the gas is supplied into the vacuum container by one or both of an injector / nozzle 130 and an intermediate nozzle 135 around the reaction chamber.

In order to prevent the gas from the peripheral nozzle 130 from being drawn out of the reaction chamber before reaching the central area of the substrate 120, the Chinese patent publication number CN102355792A discloses a technical solution for adjusting the distribution of reaction gases and free radicals in the reaction chamber. A baffle 170 is provided between the peripheral nozzle 130 and the base 110, and an opening is provided in the center region of the baffle 170. The baffle can extend the dissociation path of the reaction gas in the reaction chamber, improve the dissociation efficiency of the reaction gas, and effectively adjust the reaction. The distribution of free radicals in the cavity enables the distribution of free radicals to achieve uniform processing of the substrate.

However, in some etching processes, such as the Bosch process, the etching step and the deposition step are alternately performed in circles, and the radicals that play a major role in the deposition step are replaced by charged particles in the etching step. Because the distribution states of charged particles and free radicals are different, the baffle 170 that achieves uniform deposition of the substrate by controlling the distribution of free radicals during the deposition process may adversely affect the uniform distribution of charged particles during the etching process, that is, the baffle 170 is The beneficial effect is obvious in the deposition step, and the effect is not obvious in the etching step. Ideally, a baffle can be set in the deposition step and the baffle can be removed in the etching step, but in the actual process, because the deposition step and the etching step each have a short duration, a high switching rate is required, and parts are frequently moved in and out of the process Not only will it greatly increase the difficulty of operating the equipment, but it will also bring a large amount of particulate pollutants into the reaction chamber, which is considered to be an undesirable method.

In addition, because the size of the opening of the baffle has different influences on the plasma distribution in the reaction chamber, considering the different etching areas of different substrates, the plasma distribution requirements are different. In order to adapt to different processes, Substrate etching requires baffles with different opening sizes. However, for the same reasons as described above, moving different baffles into and out of the reaction chamber will not only increase the design difficulty, but also cause contamination to the reaction chamber and reduce the qualification rate of the product. effectiveness.

Therefore, there is a need in the industry for an improved inductively coupled reaction chamber design that can adjust the distribution and control of free radicals and charged particles in the plasma according to the needs of different processes.

In order to solve the above problems, the present invention discloses a semiconductor processing device including: a sealed reaction chamber surrounded by a top plate and a side wall of the reaction chamber; a substrate support device disposed below the insulating material window in the reaction chamber; It is used to realize the support and clamping of the substrate during the process of processing; a radio frequency power transmitting device is arranged above the top plate to emit radio frequency energy into the reaction chamber; a reaction gas injector is used to provide the A reaction gas is supplied in the reaction chamber; a carrier gas injector is disposed below the reaction gas injector, the carrier gas injector is connected to a gas controller, and the gas controller controls the carrier gas to pass through the carrier gas. Flow rate of the injector into the reaction chamber.

Preferably, the reaction gas injector includes a peripheral nozzle provided on a side wall of the reaction chamber and / or a central nozzle provided on the top plate. The reaction gas can be injected into the reaction chamber from one of the peripheral nozzle or the central nozzle, or can be simultaneously injected into the reaction chamber from the peripheral nozzle or the central nozzle.

Preferably, the carrier gas is a non-reactive gas that does not participate in the reaction of the reactive gas.

Preferably, the carrier gas injector is disposed on a side wall of the reaction chamber. The current-carrying gas injector may be a gas through-hole provided on a side wall of the reaction chamber, or may be a gas nozzle that penetrates the side wall of the reaction chamber and extends a certain length toward a central region of the reaction chamber.

Preferably, an annular baffle with an intermediate opening is provided below the reaction gas injector, and the current-carrying gas injector is a gas through hole penetrating the side wall of the reaction chamber and the annular baffle.

Preferably, the current-carrying gas injectors are distributed radially inside the baffle along the radial direction of the annular baffle.

Preferably, the current-carrying gas injector at least partially deviates from the radial direction of the annular baffle and penetrates the annular portion of the annular baffle to achieve an irregular distribution inside the baffle, in order to adjust the reaction The gas is distributed asymmetrically in the circumferential direction.

Preferably, the inner diameter of the plurality of carrier gas injectors includes one or more dimensions. By setting the inner diameter of the carrier gas injector to be the same or different, the uniform or uneven distribution of the reaction gas in the radial direction can be achieved.

Preferably, the carrier gas injector is connected to a carrier gas source through the gas controller. The gas controller is a gas flow controller, and the gas flow controller can control the flow rate of the carrier gas entering the carrier gas injector and the on-off of the switch.

Further, the present invention also discloses a plasma processing apparatus, which includes: a reaction chamber including a top plate and a sealed reaction chamber surrounded by a side wall of the reaction chamber, the top plate constituting an insulating material window; and a substrate supporting device, which is provided with Under the insulating material window in the reaction chamber; a radio frequency power transmitting device is disposed above the insulating material window to emit radio frequency energy into the reaction chamber; a reaction gas injector is used to A reaction gas is supplied in the reaction chamber; a carrier gas injector is disposed below the reaction gas injector and is used to inject a carrier gas with a certain flow rate into the center of the reaction chamber. anti- An annular air curtain extending a certain distance toward the center of the reaction chamber is formed in the reaction chamber, and the annular air curtain limits the diffusion of the reaction gas in the reaction chamber.

The distance that the annular air curtain extends toward the center direction has a positive correlation function with the flow velocity of the carrier gas.

Further, the present invention also discloses a method for manufacturing a semiconductor substrate. The method is performed in the plasma reaction chamber described above, and includes the following steps: placing a substrate to be processed on the substrate supporting device; The reaction gas injector provides a reaction gas into the reaction chamber, and at the same time starts a radio frequency power transmitting device to dissociate the reaction gas into a plasma; and injects a certain flow rate into the reaction chamber through the carrier gas injector. The carrier gas is used to limit the diffusion of the reaction gas in the horizontal direction, and the higher the flow rate of the carrier gas is, the greater the binding force on the reaction gas is; adjusting the injection of the carrier gas The carrier gas flow rate in the reactor changes the distribution of the reaction gas in the reaction chamber.

Preferably, the substrate is a silicon substrate, and the method includes an alternating etching step and a deposition step. In the etching step, the flow rate of the carrier gas injected into the reaction chamber by the carrier gas injector is lower than that in the deposition step. Carrier gas flow rate.

Preferably, the flow rate of the carrier gas injected into the reaction chamber in the etching step is greater than or equal to zero.

An advantage of the present invention is that a gas restriction device is provided below the reaction gas injector in the reaction chamber. The gas restriction device includes a plurality of carrier gas injectors for injecting a carrier gas of a certain flow rate into the reaction chamber. By adjusting the flow velocity of the carrier gas, the binding force of the carrier gas on the diffusion of the reaction gas can be effectively changed, which is equivalent to changing the opening diameter of the gas restriction device. Since the flow rate of the carrier gas is a relatively easy to control parameter, the distribution of the reaction gas in the reaction chamber is controlled by controlling the flow rate of the carrier gas into the reaction chamber. solved The problem in the conventional technology is that it is impossible to provide gas opening devices with different openings for different processes.

100, 200‧‧‧ reaction chambers

105, 205‧‧‧ sidewall

107, 207‧‧‧ insulated roof

110, 210‧‧‧ base

115, 215‧‧‧ chuck

120, 220‧‧‧ substrate

125‧‧‧Evacuator

135, 235, 335‧‧‧ center nozzle

130, 230, 330‧‧‧ peripheral nozzle

140, 240‧‧‧ antenna

145‧‧‧RF Power Source

150, 250‧‧‧ gas source

155, 255‧‧‧ pipeline

170, 270‧‧‧ bezel

230‧‧‧Injector

245‧‧‧RF Power

260, 360‧‧‧ carrier gas source

265, 365‧‧‧Gas flow controller

271‧‧‧ opening

275, 372‧‧‧ Carrier gas injector

FIG. 1 is a cross-sectional view of a conventional inductively coupled plasma reaction chamber.

Fig. 2 is a sectional view of an inductively coupled plasma reaction chamber according to an embodiment of the present invention.

Fig. 3 is a schematic diagram showing the principle of action of a carrier gas on a reaction gas in the vertical direction.

Fig. 4 shows the attenuation curve of the reaction gas in the X direction corresponding to the three Reynolds numbers.

FIG. 5 is a cross-sectional view of an inductively coupled plasma reaction chamber according to another embodiment of the present invention.

The invention discloses an inductively coupled plasma processing device and a method for manufacturing a semiconductor substrate in the device. The technical scheme of the present invention is devoted to obtaining a uniform substrate etching result, which is suitable for the Bosch process in which the etching step and the deposition step are alternately performed, and other processes that need to adjust the plasma distribution in the manufacturing process. The device and method of the present invention will be described in detail below with reference to specific embodiments and drawings.

Technologists have found that during the etching process, the main factor that determines the uniformity of substrate processing is the distribution of charged particles and free radicals in the plasma. The plasma formed by the dissociation of the reactive gas under the action of RF power is a complex substance , Including both undissociated reactive gases, as well as neutral free radicals and charged particles. The charged particles are directional under the action of bias power, and the substrate is subjected to bombardment etching in the etching process; neutral radicals are mainly used in the etching process by chemical reactions. An etching reaction or a deposition reaction is performed, and a region with a higher radical concentration has a faster etching or deposition reaction rate.

It is found in the actual manufacturing process that the distribution of free radicals in the reaction chamber is affected by the free radicals consumed in the reaction in addition to the distribution of the reaction gas that generates the plasma. When plasma processing a substrate in an inductively coupled plasma processing device, there is no etching process in the area between the edge of the substrate and the side wall of the reaction chamber. Therefore, the plasma consumption in this area is less, and free radicals in the plasma are accumulated in a large amount. Therefore, the radical concentration around the edge region of the substrate near the region is much higher than the radical concentration in the center region of the substrate, thereby causing the etching rate of the substrate edge region to be much higher than the etching rate of the center region of the substrate.

In order to restrict the distribution of the reaction gas in the reaction chamber and to shield the edge area of the substrate, in the design of the inductively coupled reaction chamber shown in Figure 1, a baffle with a central opening is provided as a gas restriction device. The baffle can guide the reaction gas injected through the peripheral nozzle 130 to flow to the central area, and use a central opening provided to adjust the distribution of the reaction gas before reaching the substrate surface. In particular, the distribution of radicals in the reaction gas, and at the same time, by providing a baffle with an opening, shielding of the edge region of the substrate is achieved, thereby reducing the concentration of free radicals in the edge region, thereby reducing the etching rate of the edge region of the substrate.

In the specific process, the use of the baffle has at least the following problems: In the process of etching the silicon substrate by the Bosch method, the baffle can greatly improve the uniformity of the substrate processing in the deposition step due to the good control of the radical distribution, but the In the step, the baffle has an adverse effect on the distribution of the charged particles in the plasma, which is not conducive to the substrate processing in the etching step. In addition, due to the different etching areas of different substrates, the free radical distribution in the reaction chamber has different effects. The specific principle is: when the substrate etching area is small, the free radical consumption in the reaction chamber is less, and the central area and edges The free radicals in the region are easy to maintain a relatively uniform distribution in the reaction chamber. When the substrate is etched with a large area, there are more free radicals involved in the etching reaction in the center region, and the free radicals consumed in the edge region are smaller due to the smaller etching area. This results in a rapid increase in the free radical concentration here. In order to ensure the uniformity of substrate processing, a substrate with a large etching area needs a baffle with a small opening size so as to cover a larger area of the edge area of the substrate. therefore, Even in the same deposition step, substrates with different etched areas are expected to be controlled by baffles with different size openings. In order to solve the above problems, ideally, by setting the opening sizes of the baffles to be different, it is possible to achieve uniform processing of substrates having different etching areas or different processing steps of the same substrate. For example, in the Bosch process, a baffle with a suitable opening size is placed in the reaction chamber during the deposition step, and the baffle is removed during the etching step or a baffle with a larger opening is replaced. However, in actual work, since the alternating speed of the deposition step and the etching step in the Bosch process is extremely fast, usually alternately looping at a speed of 1s or even less than 1s, it is impossible to achieve frequent movement of the baffle in and out of the reaction chamber. In addition, in order to meet the etching of different substrates, it is necessary to make a plurality of baffles with different sizes of openings, which not only greatly increases the processing cost of the equipment, but also prolongs the substrate processing time and reduces the applicability of the equipment. Therefore, the method of setting the baffle cannot meet the requirements of different etching processes for the opening baffles of different sizes.

In order to solve the above technical problems, the present invention designs an inductively coupled plasma reaction chamber (ICP reaction chamber). FIG. 2 shows a cross-sectional view of the ICP reaction chamber according to the first embodiment of the present invention. The ICP reaction chamber 200 includes a metal side wall 205 and an insulating top plate 207, forming an air-tight vacuum reaction chamber, and is evacuated by a vacuum pump 225. The insulating top plate 207 is merely an example, and other types of top plates may also be adopted, such as a dome shape, a metal top plate with an insulating material window, and the like. The base 210 supports a chuck 215 on which a substrate 220 to be processed is placed. Bias power is applied to the chuck 215, but it is not shown in Figure 2 because it has nothing to do with the disclosed embodiment of the invention. The RF power of the RF power source 245 is applied to an antenna 240, which is substantially coil-shaped.

The reaction gas is supplied into the reaction chamber from the reaction gas source 250 through the line 255, and the plasma is ignited and maintained under the action of radio frequency energy, so that the substrate 220 is processed. In this embodiment, the reaction gas is supplied into the vacuum space through the peripheral injector or the shower head 230, but additional gas can also be selectively injected into the reaction chamber 200 from the center shower head 235. If the gas is supplied from the injector 230 and the shower head 235 at the same time, the gas flow of each can be controlled independently. Any of these settings for injecting a reaction gas may be referred to as a reaction gas injector. In FIG. 2, a baffle 270 is disposed in the reaction chamber 200 to restrict and / or guide the gas flow emitted from the gas shower head 230. According to the component symbols, in the above embodiment The baffle plate 270 has a substantially disc shape with a hole or an opening in the middle. The baffle 270 is located below the gas shower head 230 but above the position of the substrate 220. In this way, the gas is restricted to further flow to the middle of the reaction chamber before flowing downward to the substrate, as shown by the dotted arrow in the figure.

Generally, the baffle 270 may be made of a metal material, such as anodized aluminum. The use of a metal material to make the baffle can help to limit the plasma above the baffle 270 because the RF energy from the coil is blocked by the baffle from propagating. On the other hand, the baffle 270 may be made of an insulating material, such as ceramic or quartz. In an embodiment employing an insulating baffle 270, radio frequency (RF) energy from a coil can pass through the baffle 270, so that a plasma can be maintained below the baffle 270 (shown in dotted lines), which depends on The amount of gas reaching under the baffle 270.

In this embodiment, a gas limiting device capable of dynamically adjusting the distribution of the reaction gas is provided in the reaction chamber. Specifically, the gas is implemented by the baffle 270 and a plurality of carrier gas injectors 275 provided inside the baffle 270. . The current-carrying gas injector 275 is a gas through-hole provided through the radial direction of the annular baffle, and an end thereof near the side wall 205 of the reaction chamber is provided with a gas through-hole provided inside the side wall of the reaction chamber and outside the side wall of the reaction chamber 200. The carrier gas source 260 is connected, and the carrier gas source 260 stores gas, such as Ar, N ₂ , which does not participate in the process reaction in the reaction chamber. The other end of the carrier gas injector 275 is an opening provided on a cut surface of the opening 271 of the baffle 270. The carrier gas output from the carrier gas source 260 may enter the carrier gas injector 275 through a gas control device such as a gas flow controller (MFC) 265. The gas flow controller 265 may control the carrier gas in the carrier gas source 260 It is injected into the reaction chamber 200 through a carrier gas injector 275 at a certain flow rate. When the carrier gas outputted by the carrier gas injector 275 has a certain flow rate, the carrier gas will form a ring-shaped air curtain extending along a certain distance toward the center of the reaction chamber 200 along the cut surface of the opening 271 of the ring-shaped baffle 270. The annular gas curtain formed by the carrier gas forms a certain restriction on the reaction gas and the plasma flowing downward through its annular opening, and limits the diffusion of the reaction gas and the plasma in the reaction chamber 200. The distance that the annular air curtain extends toward the center direction has a positive correlation with the flow velocity of the carrier gas injection reaction chamber. The higher the flow rate of the carrier gas at the outlet of the carrier gas injector 275, the higher the restricted opening diameter of the annular gas curtain. The smaller the restraining force on the reaction gas and the plasma is, the smaller the inner diameter of the opening of the baffle 270 is. Therefore, by controlling the flow rate of the carrier gas into the reaction chamber 200, the size of the opening of the baffle 270 can be dynamically adjusted to meet the requirements of different processes. Dynamic adjustment of the size of the opening of the baffle 270 is achieved by adjusting the binding force generated by the carrier gas. Different from the present embodiment, the current-carrying gas injector 275 is arranged along the radial direction of the baffle 270 in a fusiform shape. In another embodiment, the current-carrying gas injector 275 may be disposed away from the radial direction. The flow gas injector 275 may be provided in a spiral shape inside the baffle 270 so that the carrier gas injected into the reaction chamber 200 is distributed in a vortex shape. The carrier gas injector 275 may also be partially arranged in an irregular distribution to achieve radial non-uniform adjustment of the reaction gas.

Fig. 3 is a schematic diagram showing the principle of action of a carrier gas on a reaction gas in the vertical direction. In the ICP reaction chamber shown in FIG. 2, the reaction gas and plasma injected into the reaction chamber through the peripheral nozzle 230 and the central nozzle 235 need to pass through the opening 271 on the baffle 270 to reach the substrate surface. Therefore, the reaction gas flowing out of the peripheral nozzle 230 and the center nozzle 235 will flow downward along the y-axis direction shown in FIG. 3. During the downward flow, the reaction gas will proceed in all directions due to the diffusion characteristics of the gas. diffusion. When the reaction gas flows downward through the opening 271 of the baffle 270, the carrier gas in the carrier gas injector 275 provided in the baffle 270 is ejected at a certain flow rate in a direction opposite to the X axis shown in FIG. The reaction gas in the Y-axis direction is subjected to impact restraint. As long as the current-carrying gas injector 275 is arranged densely inside the baffle 270, the effect similar to the baffle can be used to effectively limit the distribution of the reaction gas in the Y-axis direction on the X-axis. Specifically, in the schematic diagram shown in FIG. 3, the reaction gas flow rate in the Y-axis direction is set to V _a (x), and the carrier gas flow rate in the X-axis direction is set to V _b . impact gas flow, between the V _a (x) and V _b the following relationship: Va (x) Va 0 * e ^{(-Reb * x / d)}

Among them, x is the diffusion distance of the reaction gas in the X-axis direction, d is the diameter of the carrier gas injector 275, Reb represents the Reynolds number of the carrier gas flow rate, and the larger the Reynolds number means the carrier gas flow rate V _b The larger, when X = 0, V _a (x) = V _a 0. Based on the above relationship, it can be seen that the degree of diffusion of the reaction gas in the X direction is mainly limited by the Reynolds number of the carrier gas applied to the carrier gas injector 275 and the diameter of the carrier gas injector. In order to obtain a uniform distribution of the reaction gas, the diameter of the carrier gas injector 275 can be set to be the same; in some processes, it is necessary to deliberately set the reaction gas to be non-uniform in the radial direction, so the diameter of the carrier gas injector can be set to be different.

FIG. 4 exemplarily lists the attenuation curves of the three reaction gases corresponding to the Reynolds numbers in the X direction. When the Reynolds number = 1.9, the attenuation of the reaction gas on the X axis is very slow. Even at x = 150mm, the flow velocity of the reaction gas is only attenuated by about 15%, which indicates that the carrier gas has a smaller impact on the reaction gas. The openings that restrict the reaction gas are larger. When the Reynolds number = 19, at x = 40mm, the flow velocity of the reaction gas is almost attenuated to 0. That is, when the Reynolds number = 19, the carrier gas is equivalent to forming a confinement ring with an opening diameter of 80mm. When the Reynolds number rises to 190, the velocity of the reaction gas decays faster, at 0 = 10mm, the attenuation is 0, indicating that when the Reynolds number = 190, the carrier gas forms a confinement ring with an opening diameter of 20mm for the reaction gas .

Based on the above relationship, it can be known that by adjusting the flow rate of the carrier gas, the restriction area generated by the gas restriction device formed by the baffle 270 and the carrier gas injector 275 can be enlarged or reduced. The larger the Reynolds number at the outlet of the flow gas injector 275, the smaller the restriction opening that the gas restriction device allows to allow the reaction gas to pass through. The gas-limiting device can adjust the diameter of the limiting opening to be greater than zero and smaller than or equal to the diameter of the baffle 270. When the flow velocity of the carrier gas is zero, it is equivalent to only the function of the baffle. In order to increase the dynamic adjustment range of the gas limiting device, the diameter of the baffle 270 may be set to be larger in this embodiment.

In order to adjust the dynamic adjustment range of the gas limiting device to a greater extent, FIG. 5 shows a schematic structural diagram of an ICP reaction chamber according to another embodiment. The structure of the reaction chamber in this embodiment is substantially the same as the structure of the reaction chamber in the embodiment shown in FIG. 2. For simplicity of description, the same parts use the same numbering system, and only the original “2xx” series is adjusted to the “3xx” series. The difference from the above embodiment is that in this embodiment, no baffle is provided, and the carrier gas injector 372 is a gas through hole directly provided on the side wall of the reaction chamber. In another embodiment, the carrier gas injector is It is a gas nozzle that penetrates the side wall of the reaction chamber and extends a certain distance to the central area of the reaction chamber. Carrier gas injector 372 is used to The carrier gas in the gas source 360 is injected into the reaction chamber at a certain speed to limit the diffusion of the reaction gas flowing from the central nozzle 335 and the peripheral nozzle 330 in the horizontal direction. The principle and adjustment method of the carrier gas injector 372 of this embodiment to limit the reaction gas is the same as the above embodiment, which will not be repeated here. By using the annular gas curtain formed by the carrier gas injector 372 of this embodiment, The diameter of the confinement opening can be greater than 0 and less than or equal to the radius of the reaction cavity, which can meet the requirements of more different etching processes.

The ring-shaped air curtain formed by using a carrier gas with a certain flow rate in the present invention can not only limit the reaction gas in the vertical direction, but also can guide the reaction gas injected by the peripheral nozzles in the horizontal direction. An intensive carrier gas injector is arranged on the upper side, and the carrier gas output from the carrier gas injector has a certain flow rate, and a ring-shaped gas barrier can be formed in the horizontal direction. The edge area of the substrate below it is covered. Therefore, the annular air curtain formed by the carrier gas injector of the present invention not only retains the beneficial effects of the baffle plate, but also realizes the dynamic adjustment of the restricted opening, which can meet the requirements of the Bosch process Different requirements for the size of the gas-restricted opening in different steps, and different requirements for the size of the gas-restricted opening in different etching substrates.

Both the carrier gas injector 372 or the carrier gas injector 275 of the present invention can be connected to the carrier gas source through the gas flow controller 365, so the rate of carrier gas injection into the reaction chamber can be easily adjusted. According to the above description, the flow velocity of the carrier gas has a negative correlation with the diameter of the carrier gas that constrains the reaction gas. Therefore, the gas flow controller can accurately control and adjust the gas flow rate of the carrier gas injected into the reaction chamber. Therefore, the dynamic adjustment of the constrained diameter of the annular air curtain in various sizes can be accurately realized.

In addition, those skilled in the art can easily think of other implementation manners through the understanding of the description of the present invention and the practice of the present invention. Various aspects and / or components in the various embodiments described herein may be adopted individually or in combination. It should be emphasized that the description and examples are merely examples, and the actual scope and ideas of the present invention are defined by the following patent application scope.

Claims (21)

A plasma processing apparatus includes: a reaction chamber including a top plate and a sealed reaction chamber surrounded by a side wall of the reaction chamber, the top plate constituting a window of insulating material; and a substrate supporting device provided on the substrate. Below the insulating material window in the reaction chamber; a radio frequency power transmitting device is disposed above the insulating material window to emit radio frequency energy into the reaction chamber; a reaction gas injector is used to supply into the reaction chamber A reaction gas; a carrier gas injector arranged below the reaction gas injector, the carrier gas injector is connected to a gas controller, and the gas controller controls a carrier gas to be injected through the carrier gas injector The flow rate of the reaction chamber. The plasma processing apparatus according to item 1 of the scope of patent application, wherein the carrier gas is a non-reactive gas that does not participate in the reaction of the reactive gas. The plasma processing device according to item 1 of the scope of the patent application, wherein the current-carrying gas injector is a gas through hole provided on a side wall of the reaction chamber. The plasma processing device according to item 1 of the scope of the patent application, wherein the current-carrying gas injector is a gas nozzle that penetrates the side wall of the reaction chamber and extends a distance into the reaction chamber. The plasma processing device according to item 1 of the scope of patent application, wherein a ring baffle with a middle opening is provided below the reaction gas injector, and the current-carrying gas injector penetrates the side wall of the reaction chamber and the ring. Gas through holes in the baffle. The plasma processing device according to item 5 of the scope of patent application, wherein the current-carrying gas injector is distributed radially inside the annular baffle along a radial direction of the annular baffle. The plasma processing device according to item 5 of the scope of patent application, wherein the current-carrying gas injector at least partially deviates from the radial direction of the annular baffle through the annular portion of the annular baffle, and is realized inside the annular baffle. Irregular distribution. The plasma processing device according to item 1 of the scope of the patent application, wherein the inner diameter of the plurality of current-carrying gas injectors is set to one or more dimensions. The plasma processing device according to item 1 in the scope of the patent application, wherein the carrier gas injector is connected to a carrier gas source through the gas controller, the gas controller is a gas flow controller, and the gas flow rate The controller can control the flow rate of the carrier gas entering the carrier gas injector and the on-off of the switch. A plasma processing apparatus includes: a reaction chamber including a top plate and a sealed reaction chamber surrounded by a side wall of the reaction chamber, the top plate constituting a window of insulating material; and a substrate supporting device provided on the substrate. Below the insulating material window in the reaction chamber; a radio frequency power transmitting device is disposed above the insulating material window to emit radio frequency energy into the reaction chamber; a reaction gas injector is used to supply into the reaction chamber A reaction gas; a carrier gas injector arranged below the reaction gas injector for injecting a carrier gas of a certain flow rate into the center of the reaction chamber, and a carrier gas having a certain velocity in the reaction chamber An annular air curtain is formed that extends a certain distance toward the center of the reaction chamber, and the annular air curtain limits the diffusion of the reaction gas in the reaction chamber. The plasma processing device according to item 10 of the scope of the patent application, wherein the distance of the annular air curtain extending toward the center and the flow velocity of the carrier gas have a positive correlation function. The plasma processing device according to item 10 of the patent application scope, wherein the carrier gas injector is connected to a gas flow controller, and the gas flow controller controls the flow rate of the carrier gas into the reaction chamber. The plasma processing apparatus according to item 10 of the scope of the patent application, wherein the current-carrying gas injector is a gas through hole provided on a side wall of the reaction chamber. The plasma processing apparatus according to item 10 of the scope of the patent application, wherein the current-carrying gas injector is a gas nozzle that penetrates the side wall of the reaction chamber and extends a distance into the reaction chamber. The plasma processing device according to item 10 of the patent application scope, wherein a ring baffle with a middle opening is provided below the reaction gas injector, and the current-carrying gas injector penetrates the side wall of the reaction chamber and the ring shape. Gas through holes in the baffle. The plasma processing device according to item 15 of the scope of the patent application, wherein the current-carrying gas injector is distributed radially inside the annular baffle along a radial direction of the annular baffle. The plasma processing device according to item 15 of the scope of patent application, wherein the carrier gas injector at least partially deviates from the radial direction of the annular baffle and penetrates the annular portion of the annular baffle to realize inside the annular baffle. Irregular distribution. A method for processing a semiconductor substrate, the method is performed in a plasma processing device according to any one of claims 1 to 17, wherein the method includes the following steps: placing a substrate to be processed on the substrate support On the device; supplying a reaction gas into the reaction chamber through the reaction gas injector, and simultaneously starting the radio frequency power transmitting device to dissociate the reaction gas into a plasma; into the reaction chamber through the carrier gas injector A carrier gas of a certain flow rate is injected; the carrier gas forms a ring-shaped air curtain in the reaction chamber that extends a certain distance toward the center of the reaction chamber, and the ring-shaped air curtain restricts the diffusion of the reaction gas in the reaction chamber; adjusting the carrier gas The flow rate of the carrier gas in the flow gas injector is to change the distance that the annular gas curtain extends toward the center, so as to adjust the distribution of the reaction gas. The method for processing a semiconductor substrate according to item 18 of the scope of patent application, wherein the substrate is a silicon substrate, and the method includes an etching step and a deposition step performed alternately, in which the carrier gas injector is injected into the reaction chamber. The carrier gas flow rate is lower than the carrier gas flow rate during the deposition step. The method for processing a semiconductor substrate according to item 19 of the scope of patent application, wherein the flow rate of the carrier gas injected into the reaction chamber in the etching step is greater than or equal to zero. The method for processing a semiconductor substrate according to item 18 of the scope of patent application, wherein the carrier gas does not participate in a reaction process of the reaction gas.