# US 2014/0193977 A1 · Plasma etching method and plasma etching apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0193977 A1 - Document ID: US20140193977A1 - Status: Published application - Kind: A1 - Application number: 14/238,552 - Filed: 2012-08-28 - Published: 2014-07-10 - Earliest claimed: 2011-08-31 - Assignees: Tokyo Electron Limited - Inventors: Masaya Kawamata; Masanobu Honda; Kazuhiro Kubota - Web page: https://patentgrep.com/patent/US20140193977A1 ## CPC - H10P 72/0421: {for drying etching} - H01J 37/32091: {the radio frequency energy being capacitively coupled to the plasma} - H01J 37/32449: {Gas control, e.g. control of the gas flow} - H10P 50/242: {of Group IV materials} - H10P 50/283: {by chemical means} - H10P 72/0434: {mainly by convection} - H10P 72/0602: {Temperature monitoring} - H10P 72/72: using electrostatic chucks - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract A plasma etching apparatus includes a processing chamber; a holding unit for holding the substrate within the processing chamber; an electrode plate facing the holding unit; a plurality of supply parts arranged at different radial positions with respect to the substrate for supplying processing gas to a space between the holding unit and the electrode plate; a high frequency power supply that supplies high frequency power to the holding unit and/or the electrode plate to convert the processing gas supplied to the space into plasma; an adjustment unit that adjusts a supply condition for each of the supply parts; and a control unit that controls the adjustment unit to vary the supply condition between a position where an effect of diffusion of processing gas on an active species concentration distribution at the substrate is dominant and a position where an effect of flow of the processing gas is dominant. ## Claims ### Claim 1 A plasma etching apparatus that etches a substrate using a processing gas converted into plasma, the plasma etching apparatus comprising: a processing chamber; a holding unit that is arranged within the processing chamber and is configured to hold the substrate; an electrode plate that is arranged to face the holding unit within the processing chamber; a plurality of supply parts for supplying processing gas to a space between the holding unit and the electrode plate, the supply parts being arranged at different positions with respect to a radial direction of the substrate; a high frequency power supply that converts the processing gas supplied to the space from the plurality of supply parts into plasma by supplying a high frequency power to at least one of the holding unit and the electrode plate; an adjustment unit that adjusts a supply condition for supplying processing gas with respect to each of the plurality of supply parts; and a control unit that controls the adjustment unit to vary the supply condition to be adjusted between a first position and a second position, the first position being where an effect of diffusion of supplied processing gas is greater than an effect of flow of supplied processing gas on an active species concentration distribution of active species contained in the plasma-converted processing gas at the substrate, and the second position being where the effect of flow of supplied processing gas is greater than the effect of diffusion of supplied processing gas on the active species concentration distribution at the substrate. ### Claim 2 (depends on 1) The plasma etching apparatus as claimed in claim 1, wherein the plurality of supply parts include a first supply part for supplying processing gas to a center portion toward a radial center of the substrate and a second supply part for supplying processing gas to a substrate portion toward a radial periphery of the substrate with respect to the center portion; the control part controls the adjustment unit to adjust a first supply condition for supplying processing gas from the second supply part if the effect of diffusion is greater than the effect of flow on the active species concentration distribution at the substrate portion where the processing gas is supplied from the second supply part; and the control unit controls the adjustment unit to adjust a second supply condition for supplying processing gas from the first supply part if the effect of flow is greater than the effect of diffusion on the active species concentration distribution at the substrate portion where the processing gas is supplied from the second supply part. ### Claim 3 (depends on 2) The plasma etching apparatus as claimed in claim 2, wherein assuming u denotes a processing gas flow rate and D denotes a processing gas diffusion coefficient at the substrate portion where the processing gas is supplied from the second supply part, and L denotes a distance between the holding unit and the electrode plate, the effect of diffusion is greater than the effect of flow in a case where a Peclet number calculated by uL/D is less than one; and the effect of flow is greater than the effect of diffusion in a case where the Peclet number calculated by uL/D is greater than one. ### Claim 4 (depends on 2) The plasma etching apparatus as claimed in claim 2, wherein the first supply condition and the second supply condition correspond to a processing gas supply flow rate. ### Claim 5 (depends on 2) The plasma etching apparatus as claimed in claim 2, wherein the first supply part and the second supply part are configured to mix at least two processing gases and supply the mixed processing gas; and the first supply condition and the second supply condition correspond to a mix ratio at which the at least two processing gases are mixed. ### Claim 6 (depends on 2) The plasma etching apparatus as claimed in claim 2, wherein the first supply part includes a first supply hole formed at a first portion of a plurality of portions into which the electrode plate is subdivided concentrically with respect to a center position facing a center of the substrate held by the holding unit, the first supply part being configured to supply processing gas to the space via the first supply hole; and the second supply part includes a second supply hole formed at a second portion toward the radial periphery of the substrate with respect to the first portion of the plurality of portions, the second supply part being configured to supply processing gas to the space via the second supply hole. ### Claim 7 (depends on 6) The plasma etching apparatus as claimed in claim 6, further comprising: an electrode support plate that is arranged at a side of the electrode plate opposite the holding unit and is configured to support the electrode plate; wherein the first supply part and the second supply part respectively include a first buffer chamber and a second buffer chamber that are formed inside the electrode support plate or between the electrode support plate and the electrode plate, the first buffer chamber and the second buffer chamber being subdivided concentrically with respect to a center position facing the center of the substrate held by the holding unit; the first supply hole communicates with the first buffer chamber; and the second supply hole communicates with the second buffer chamber. ### Claim 8 A plasma etching method for etching a substrate using a processing gas converted into plasma, the plasma etching method comprising: a holding step of holding the substrate with a holding unit arranged within a processing chamber; a processing gas supplying step of supplying processing gas to a space between the holding unit and an electrode plate facing the holding unit within the processing chamber, the processing gas being supplied from a plurality of supply parts arranged at different positions with respect to a radial direction of the substrate; and a high frequency power supplying step of converting the processing gas supplied to the space from the plurality of supply parts into plasma by supplying a high frequency power from a high frequency power supply to at least one of the holding unit and the electrode plate; wherein the processing gas supplying step includes controlling an adjustment unit configured to adjust a supply condition for supplying processing gas with respect to each of the plurality of supply parts such that the supply condition that is adjusted varies between a first position and a second position, the first position being where an effect of diffusion of supplied processing gas is greater than an effect of flow of supplied processing gas on an active species concentration distribution of active species contained in the plasma-converted processing gas at the substrate, and the second position being where the effect of flow of supplied processing gas is greater than the effect of diffusion of supplied processing gas on the active species concentration distribution at the substrate. ### Claim 9 (depends on 8) The plasma etching method as claimed in claim 8, wherein the plurality of supply parts include a first supply part for supplying processing gas to a center portion toward a radial center of the substrate and a second supply part for supplying processing gas to a substrate portion toward a radial periphery of the substrate with respect to the center portion; and the processing gas supplying step includes controlling the adjustment unit to adjust a first supply condition for supplying processing gas from the second supply part if the effect of diffusion is greater than the effect of flow on the active species concentration distribution at the substrate portion where the processing gas is supplied from the second supply part; and controlling the adjustment unit to adjust a second supply condition for supplying processing gas from the first supply part if the effect of flow is greater than the effect of diffusion on the active species concentration distribution at the substrate portion where the processing gas is supplied from the second supply part. ### Claim 10 (depends on 9) The plasma etching method as claimed in claim 9, wherein in the processing gas supplying step, assuming u denotes a processing gas flow rate and D denotes a processing gas diffusion coefficient at the substrate portion where the processing gas is supplied from the second supply part, and L denotes a distance between the holding unit and the electrode plate, the effect of diffusion is greater than the effect of flow in a case where a Peclet number calculated by uL/D is less than one; and the effect of flow is greater than the effect of diffusion in a case where the Peclet number calculated by uL/D is greater than one. ### Claim 11 (depends on 9) The plasma etching method as claimed in claim 9, wherein the first supply condition and the second supply condition correspond to a processing gas supply flow rate. ### Claim 12 (depends on 9) The plasma etching method as claimed in claim 9, wherein the first supply part and the second supply part are configured to mix at least two processing gases and supply the mixed processing gas; and the first supply condition and the second supply condition correspond to a mix ratio at which the at least two processing gases are mixed. ### Claim 13 (depends on 9) The plasma etching method as claimed in claim 9, wherein the first supply part includes a first supply hole formed at a first portion of a plurality of portions into which the electrode plate is subdivided concentrically with respect to a center position facing a center of the substrate held by the holding unit, the first supply part being configured to supply processing gas to the space via the first supply hole; and the second supply part includes a second supply hole formed at a second portion toward the radial periphery of the substrate with respect to the first portion of the plurality of portions, the second supply part being configured to supply processing gas to the space via the second supply hole. ### Claim 14 (depends on 13) The plasma etching apparatus as claimed in claim 13, wherein the first supply part and the second supply part respectively include a first buffer chamber and a second buffer chamber that are formed inside an electrode support plate arranged at a side of the electrode plate opposite the holding unit or between the electrode support plate and the electrode plate, the first buffer chamber and the second buffer chamber being subdivided concentrically with respect to a center position facing the center of the substrate held by the holding unit; the first supply hole communicates with the first buffer chamber; and the second supply hole communicates with the second buffer chamber.