Classifications

• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
  • H10D84/00—Integrated devices formed in or on semiconductor substrates that comprise only semiconducting layers, e.g. on Si wafers or on GaAs-on-Si wafers
  • H10D84/01—Manufacture or treatment
  • H10D84/02—Manufacture or treatment characterised by using material-based technologies
  • H10D84/03—Manufacture or treatment characterised by using material-based technologies using Group IV technology, e.g. silicon technology or silicon-carbide [SiC] technology
  • H10D84/038—Manufacture or treatment characterised by using material-based technologies using Group IV technology, e.g. silicon technology or silicon-carbide [SiC] technology using silicon technology, e.g. SiGe
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
  • H10D30/00—Field-effect transistors [FET]
  • H10D30/01—Manufacture or treatment
  • H10D30/021—Manufacture or treatment of FETs having insulated gates [IGFET]
  • H10D30/024—Manufacture or treatment of FETs having insulated gates [IGFET] of fin field-effect transistors [FinFET]
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
  • H10D62/00—Semiconductor bodies, or regions thereof, of devices having potential barriers
  • H10D62/10—Shapes, relative sizes or dispositions of the regions of the semiconductor bodies; Shapes of the semiconductor bodies
  • H10D62/17—Semiconductor regions connected to electrodes not carrying current to be rectified, amplified or switched, e.g. channel regions
  • H10D62/213—Channel regions of field-effect devices
  • H10D62/221—Channel regions of field-effect devices of FETs
  • H10D62/235—Channel regions of field-effect devices of FETs of IGFETs
  • H10D62/292—Non-planar channels of IGFETs
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
  • H10D84/00—Integrated devices formed in or on semiconductor substrates that comprise only semiconducting layers, e.g. on Si wafers or on GaAs-on-Si wafers
  • H10D84/01—Manufacture or treatment
  • H10D84/0123—Integrating together multiple components covered by H10D12/00 or H10D30/00, e.g. integrating multiple IGBTs
  • H10D84/0126—Integrating together multiple components covered by H10D12/00 or H10D30/00, e.g. integrating multiple IGBTs the components including insulated gates, e.g. IGFETs
  • H10D84/0165—Integrating together multiple components covered by H10D12/00 or H10D30/00, e.g. integrating multiple IGBTs the components including insulated gates, e.g. IGFETs the components including complementary IGFETs, e.g. CMOS devices
  • H10D84/0167—Manufacturing their channels
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
  • H10D84/00—Integrated devices formed in or on semiconductor substrates that comprise only semiconducting layers, e.g. on Si wafers or on GaAs-on-Si wafers
  • H10D84/01—Manufacture or treatment
  • H10D84/0123—Integrating together multiple components covered by H10D12/00 or H10D30/00, e.g. integrating multiple IGBTs
  • H10D84/0126—Integrating together multiple components covered by H10D12/00 or H10D30/00, e.g. integrating multiple IGBTs the components including insulated gates, e.g. IGFETs
  • H10D84/0165—Integrating together multiple components covered by H10D12/00 or H10D30/00, e.g. integrating multiple IGBTs the components including insulated gates, e.g. IGFETs the components including complementary IGFETs, e.g. CMOS devices
  • H10D84/0193—Integrating together multiple components covered by H10D12/00 or H10D30/00, e.g. integrating multiple IGBTs the components including insulated gates, e.g. IGFETs the components including complementary IGFETs, e.g. CMOS devices the components including FinFETs
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
  • H10D84/00—Integrated devices formed in or on semiconductor substrates that comprise only semiconducting layers, e.g. on Si wafers or on GaAs-on-Si wafers
  • H10D84/80—Integrated devices formed in or on semiconductor substrates that comprise only semiconducting layers, e.g. on Si wafers or on GaAs-on-Si wafers characterised by the integration of at least one component covered by groups H10D12/00 or H10D30/00, e.g. integration of IGFETs
  • H10D84/82—Integrated devices formed in or on semiconductor substrates that comprise only semiconducting layers, e.g. on Si wafers or on GaAs-on-Si wafers characterised by the integration of at least one component covered by groups H10D12/00 or H10D30/00, e.g. integration of IGFETs of only field-effect components
  • H10D84/83—Integrated devices formed in or on semiconductor substrates that comprise only semiconducting layers, e.g. on Si wafers or on GaAs-on-Si wafers characterised by the integration of at least one component covered by groups H10D12/00 or H10D30/00, e.g. integration of IGFETs of only field-effect components of only insulated-gate FETs [IGFET]
  • H10D84/85—Complementary IGFETs, e.g. CMOS
  • H10D84/853—Complementary IGFETs, e.g. CMOS comprising FinFETs
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P50/00—Etching of wafers, substrates or parts of devices
  • H10P50/20—Dry etching; Plasma etching; Reactive-ion etching
  • H10P50/24—Dry etching; Plasma etching; Reactive-ion etching of semiconductor materials
  • H10P50/242—Dry etching; Plasma etching; Reactive-ion etching of semiconductor materials of Group IV materials
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P50/00—Etching of wafers, substrates or parts of devices
  • H10P50/20—Dry etching; Plasma etching; Reactive-ion etching
  • H10P50/28—Dry etching; Plasma etching; Reactive-ion etching of insulating materials
  • H10P50/282—Dry etching; Plasma etching; Reactive-ion etching of insulating materials of inorganic materials
  • H10P50/283—Dry etching; Plasma etching; Reactive-ion etching of insulating materials of inorganic materials by chemical means

Definitions

• This application relates to production of FinFET structures with pitch below twenty (20) nanometers (nm).
• Fin-type field-effect transistors are increasingly being used to effectively scale integrated circuits. FinFETs, which have a vertical fin structure that function as channels, occupy less horizontal space on the semiconductor substrate and can be formed in logic areas and in memory areas through general semiconductor patterning processes.
• a method of forming fins of a two-fin FinFET device includes forming mandrels with a lithographic etch process; forming sidewall spacers on the mandrels; and forming fins on the sidewall spacers, wherein the two-fin FinFET device is formed on each of the sidewall spacers.
• a method of forming a multi-fin device can include forming one or more mandrels with a first pitch and a first width; forming sidewall spacers on each side of the one or more mandrels, the sidewall spacers each having a second width; and forming fins on sides of the sidewall spacers, wherein the fins have a pitch of less than 20nm.
• Figure 1 A shows a planar view of a multi-fin FinFET device.
• Figure IB shows a cross-sectional view of a multi-fin FinFET device.
• Figure 2 illustrates an example process for producing a FinFET device.
• Figure 3 illustrates another example process for producing a FinFET device.
• Figure 4 illustrates an example process according to some embodiments of the present invention for producing a FinFET device.
• Figure 5 illustrates another example process according to some embodiments of the present invention for producing a FinFET device.
• FIGS 1 A and IB illustrate a FinFET structure 100.
• FinFET structure 100 includes one or more parallel fins 104-1 through 104-N formed on a substrate 102.
• a gate structure 106 is deposited over fins 104-1 through 104-N.
• Modern structures may include two or more fins 104 that are uniformly separated by a pitch P.
• the FinFET devices can be nMOS or pMOS devices, depending on the formation of fins 104-1 through 104-N.
• Figure IB illustrates a cross-sectional view of structure 100 illustrated in Figure 1 A.
• the pitch P is defined by the space between two fins and the width of the fin, as shown in Figure 1A.
• FinFET structure 100 illustrated in Figures 1 A and IB have increased the device density dramatically, increasing the device density further leads to a need for small feature sizes and smaller pitches for the FinFET structures that are used.
• the technology has exceeded the limits of current lithographic technologies to produce FinFET structures with higher pitches.
• scaling the fin pitch to below 20 nm is desirable to scale logic cell height and thus overall chip sizes.
• SADP self-aligned double processing
• a group of mandrels are formed lithographically by patterning and etching a mandrel material.
• Sidewall spacers can then be formed on the sidewalls of the mandrels.
• the formation of sidewall spacers can be accomplished by depositing material over the mandrel material, removing the deposited material on the horizontal surfaces, and removing the mandrel material leaving the sidewall spacers. Deposition of sidewall spacers can result in spacer widths that are much smaller than those available with lithographic formation of the mandrels.
• the sidewall spacers and mandrels can then be polished to expose the mandrels and the spacers used as an etch mask for removal of the remaining mandrel materials.
• the SADP process involves forming a spacer as a film layer on the sidewall of the pre-patterned mandrels, removing the spacer layer from the horizontal surfaces, and removing the originally patterned mandrel material leaving the spacers themselves. Since there are two side-wall spacers for every mandrel, the line density has now doubled.
• SADP is applicable for defining narrow gates at half the original lighographic pitch.
• This spacer approach can, theoretically, be repeated to successively half the pitch between spacers.
• a second SADP procedure referred to as a self-aligned quadruple patterning (SAQP)
• SAQP self-aligned quadruple patterning
• Figure 2 illustrates a SAQP process 200. As illustrated in Figure 2, mandrels 202-1 through 202-4 are deposited with a pitch of PI . Figure 2 illustrates mandrels 202-1 through 202- 4, however any number of mandrels 202 may be formed. As discussed above, mandrels 202 are patterned and etched using a lithographic process.
• Sidewall spacers 204-1 through 204-8 are then formed on mandrels 202-1 through 202-4 in an SADP process by deposition of sidewall materials on mandrels 202, removal of the sidewall materials on the horizontal surfaces, and etching to remove mandrels 202.
• sidewall spacers 204-1 and 204-2 are formed on opposite sides of mandrel 202-1
• sidewall spacers 204-3 and 204-4 are formed on opposite sides of mandrel 202-2
• sidewall spacers 204-5 and 204-6 are formed on opposite sides of mandrel 202-3
• sidewall spacers 204-7 and 204-8 are formed on opposite sides of mandrel 202-4.
• sidewall spacers 206-1 through 206-8 and fins 208-1 through 208-8 are formed on the sidewalls of sidewall spacers 204.
• sidewall spacer 206-1 and fin 208-1 are formed on opposite sides of sidewall spacer 204-1
• fin 208-2 and sidewall spacer 206-2 are formed on opposite sides of sidewall spacer 204-2
• sidewall spacer 206-3 and fin 208-3 are formed on opposite sides of sidewall spacer 204-3
• fin 208-4 and sidewall spacer 206-4 are formed on opposite sides of sidewall spacer 204-4
• sidewall spacer 206-4 and fin 208-5 are formed on opposite sides of sidewall spacer 204-5
• fin 208-6 and sidewall spacer 206-6 are formed on opposite sides of sidewall spacer 204-6
• sidewall spacer 206-7 and fin 208-7 are formed on opposite sides of sidewall spacer 204-7
• fin 208-8 and sidewall spacer 206-8 are formed on opposite sides of sidewall spacer 204
• Spacers 204-1 through 204-8 as well as spacers 206-1 through 206-8 are then removed, leaving fins 208-1 through 208-8.
• fins 208-1 and 208-2 form part of a two-fin FinFET device; fins 208-3 and 208-4 form part of a two-fin FinFET device; fins 208-5 and 208-6 form part of a two-fin FinFET device; and fins 208-7 and 208-8 form part of a two-fin FinFET device.
• only one fin 208 is formed on each of sidewall spacers 206.
• the pitch between deposited devices is halved. Consequently, if the pitch between mandrels 202 is PI, the pitch between spacers 204 is Pl/2, and the final pitch between fins 208 that are in a single device is Pl/4. Further, the pitch between devices is PI . Using the limitations of the 193 nm
• PI 80 nm and the pitch between fins is 20nm. Consequently, a SAQP as illustrated in Figure 2 cannot produce a pitch size that is less than 20nm between fins.
• FIG 3 illustrates a self-aligned octuplet process (SAOP), which can achieve a less than 20 nm pitch with the 193nm lithographic process.
• the SAOP is performed by three successive SADP processes, resulting in a pitch that is 1/8 that of the pitch between the mandrels.
• a lithographic process is used to pattern mandrels 302-1 and 302-2.
• Mandrels 302 are deposited with a pitch of P2.
• sidewall spacers 304 are then deposited on mandrels 302.
• sidewall spacers 304-1 and 304-2 are formed on opposite sides of mandrel 302-1 and sidewall spacers 304-3 and 3-4-4 are formed on the opposite sides of mandrel 302-2.
• Mandrels 302 are then removed, leaving sidewall spacers 304.
• sidewall spacers 304 have a pitch of P2/2.
• sidewall spacers 306 are formed on sidewall spacers 304 and sidewall spacers 304 removed.
• sidewall spacers 306-1 and 306-2 are formed on opposite sides of sidewall spacer 304-1; sidewall spacers 306-3 and 306-4 are formed on opposite sides of sidewall spacer 304-2; sidewall spacers 306-5 and 306-6 are formed on opposite sides of sidewall spacers 304-3; and sidewall spacers 306-7 and 306-8 are formed on opposite sides of sidewall spacers 304-4.
• the pitch between sidewall spacers 306 is now P2/4.
• sidewall spacers 307 and fins 308 are formed on sidewall spacers 306, after which both spacers 307 and spacers 306 are removed leaving fins 308.
• sidewall spacer 307-1 and fin 308-1 are formed on opposite sides of sidewall spacer 306-1
• fin 308-2 and sidewall spacer 307-2 are formed on opposite sides of sidewall spacer 306-2
• sidewall spacer 307-3 and fin 308-3 are formed on opposite sides of sidewall spacer 306-3
• fin 308-4 and sidewall spacer 307-4 are formed on opposite sides of sidewall spacer 306-4
• sidewall spacer 307-5 and fin 308-5 are formed on opposite sides of sidewall spacer 306-5
• fin 308-6 and sidewall spacer 307-6 are formed on opposite sides of sidewall spacer 306-6
• sidewall spacer 307-7 and fin 308-7 are formed on opposite sides of sidewall spacer 306-7
• fin 308-8 and sidewall spacer 307-8 are formed on opposite sides
• P2 is, for example, 128nm
• P2/2 is 64nm
• P2/4 is 32nm
• P2/8 is 16nm. Consequently, a pitch of 16nm is achievable, with a device separation (after the removal of dummy fins or sidewall spacers 307 of 32nm, using the SAOP process.
• the third SADP process required to achieve requires too many process steps, increasing costs and complicating the process, and is difficult to achieve within the constraints of materials depositions processes.
• Figure 4 illustrates an example of a SAQP process according to some embodiments of the present invention for achieving a two-fin device with a pitch of less than 20 nm.
• mandrels 402 are deposited in a lithographic process.
• Mandrels 402-1 and 402-2 are illustrated in Figure 4.
• Mandrels 402-1 and 402-2 are deposited with a pitch P3 and width Wl .
• Sidewall spacers 404 are deposited on the sidewalls of mandrels 402. Consequently, sidewall spacers 404-1 and 404-2 are formed on opposite sides of mandrel 402-1 and sidewall spacers 404-3 and 404-4 are formed on opposite sides of mandrel 402-2.
• the width W2 of sidewall spacers 404 is arranged to affect the final pitch of fins 406.
• fins 406 are formed on the sidewalls of side-wall spacers 404.
• fins 406-1 and 406-2 are formed on opposite sides of sidewall spacer 404-1; fins 406-3 and 406-4 are formed on opposite sides of sidewall spacer 404-2; fins 406-5 and 506- 6 are formed on opposite sides of sidewall spacer 404-3; and fins 406-7 and 406-8 are formed on opposite sides of sidewall spacer 404-4.
• the width W2 of sidewall spacers 404 and the width W3 of fins 406 are the same.
• mandrels 402 may be formed with a pitch of P3. Fins 406 in each device have a pitch of P and devices have a pitch separation of D.
• the pitch P can be made 16nm if the width W2 of sidewall spacers 404 and W2 of fins 406 sum to 16 nm.
• W2 and W3 are both 8 nm, which is an achievable dimension for deposition of sidewall materials using a 7nm process technology, then the pitch P is 16 nm.
• the pitch of sidewall spacers 404 PS can be arranged to be P3/2 by varying the widthWl of mandrels 402 and the width of spacers W2.
• the separation D between the resulting two-fin devices is given by the sum of Wl and W2.
• the spacing between mandrels 402 may not result in an even distance between each of sidewall spacers 404.
• fins with small pitch, pitch less than 20nm are formed in a process that includes formation of mandrels 402 with a width of Wl and pitch of P3 with a lithographic etch process.
• Sidewall spacers 404 are formed by deposition of material on the sides of mandrels 402, and mandrel material is removed to leave sidewall spacers 404.
• Sidewall spacers 404 each have a width W2 and sidewall spacers have a pitch of PS.
• Fins 406 are then formed on the sidewall of spacers 404, with each spacer 404 providing for a single two- fin device formation.
• the mandrel pitch P3 can be used to separate MOS from PMOS FinFET devices.
• the example embodiment of the present invention illustrated in Figure 4 can produce fin pitches of less than 20nm primarily because the fin pitch is dependent only on the ability to deposit sidewall spacers 404 and fins 406 within a particular width.
• those deposition widths can be as low as 7 nm, and 8nm widths or above are available.
• Figure 5 illustrates an example of a process according to some embodiments of the present invention for producing a multi-fin FinFET device where the number of fins is greater than two. Although, due to the limitations of the process technologies, fin pitches of less than 20nm may not be easily achieved, the process illustrated in Figure 5 can be used to produce multi-fin devices where the fin-pitch can be larger than 20nm.
• mandrels 502 are formed with a lithographic and etch process.
• Mandrels 502 (mandrels 502-1 through 502-4 are illustrated) have a pitch of P4 and a width of Wl, within the limits of resolution of the lithographic process.
• sidewall spacers 504 are formed on mandrels 502.
• sidewall spacers 504-1 and 504-3 are formed on opposite sides of mandrel 502-1 ; sidewall spacers 504-3 and 504-4 are formed on opposite sides of mandrel 502-2; sidewall spacers 504-5 and 504-6 are formed on opposite sides of mandrel 502-3; and 504-7 and 504-8 are formed on opposite sides of mandrel 502-4.
• fins 506 and sacrificial sidewall spacers 507 are formed on sidewall spacers 504.
• Figure 5 illustrates production of a 3-fin device, however, a four-fin device can also be produced using sidewalls 504 on a single mandrel 502. A device with more than four fins can be produced using sidewalls 504 from adjacent mandrels 502.
• fins for each device may span adjacent mandrels 502.
• fins 506-1 and 506-2 are formed on opposite sides of sidewall spacer 504-1.
• Sacrificial spacers 507-1 and 507-2 formed on opposite sides of sidewall spacer 504-2 during the formation of fins 506 and removed.
• Fins 506-3 and 506-4 are formed on opposite sides of sidewall spacer 504-3 and fin 506-5, which forms the third fin of a device that includes fins 506-3, 506, and 506-5, is formed on a first side of sidewall spacer 504- 4.
• Sacrificial spacer 507-3 is formed on a second side of sidewall spacer 504-4.
• sacrificial sidewall spacer 507-4 and fin 506-6 are formed on opposite sides of sidewall spacer 504-5; fins 506-7 and 506-8 are formed on opposite sides of sidewall spacer 504-6; sacrificial sidewall spacers 507-5 and 507-6 are formed on opposite sides of sidewall spacer 504-7; and fins 506-9 and 506-10 are formed on opposite sides of sidewall spacer 504-8.
• the spacing between fins 506 is determined by width W2 of sidewall spacer 504.
• the fin pitch which is shown as P4/4 as an example in Figure 5, is given by the sum of the width W2 of sidewall spacer 504 and the width W3 of sidewall spacer w3.
• the width of mandrel 502, Wl can be adjusted to produce an overall pitch of P4/4 for the multi-fin device.
• the width of spacers 504, W2, and the width of fins 506, W3, are the same.

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• Insulated Gate Type Field-Effect Transistor (AREA)
• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Plasma & Fusion (AREA)
• Metal-Oxide And Bipolar Metal-Oxide Semiconductor Integrated Circuits (AREA)
• Bipolar Transistors (AREA)

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• 2016
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