Patent Application
20240068619
Embodiments of the disclosure generally relate to apparatus and methods for delivering precursors. More particularly, embodiments of the disclosure are directed to ampoules having constant headspace for uniform precursor delivery to processing chambers.
In a semiconductor wafer processing chamber, such as an atomic layer deposition (ALD) chamber, it is useful to control the delivery of precursor during deposition. Changes in precursor concentration during the deposition process can result in non-uniform film deposition.
During processing, precursor molecules are delivered to a processing chamber in a gaseous state. For liquid precursors, a flow of a carrier gas, typically an inert gas, is passed through an ampoule containing the precursor. The precursor molecules in the headspace are swept up in the stream of carrier gas and flow to the processing chamber. The headspace, also referred to as a saturation zone, can change due to use of the precursor or refilling of the ampoule so that the overall size of the saturation zone varies during deposition processes. As the level of liquid in the ampoule changes, the volume of the headspace changes causing variations in the concentration of the precursor in the carrier gas resulting in deposition non-uniformity.
There is, therefore, a need in the art for apparatus and methods to improve precursor concentration uniformity during deposition processes.
One or more embodiments of the disclosure are directed to ampoules comprising a housing, a lid, and a floating structure. The housing has a sidewall and a bottom. The lid is positioned on a top surface of the sidewall. The lid has an inlet opening and an outlet opening. The floating structure is within the housing and comprises a float, and outlet channel, and a baffle. The float has a top surface and a volume configured to displace a predetermined volume of liquid so that the top surface of the float remains a depth below a surface of the liquid. The outlet channel extends from a top surface of the float. A baffle has a top surface and a bottom surface defining a thickness of the baffle. The baffle is positioned along a length of the outlet channel to create a saturation zone between the bottom surface of the baffle and the surface of the liquid. At least one opening is in the outlet channel between the top surface of the float and the bottom surface of the baffle.
Additional embodiments of the disclosure are directed to ampoules comprising a housing, a lid, and a floating structure. The housing has a sidewall and a bottom. The lid is positioned on a top surface of the sidewall. The lid has an inlet opening and an outlet opening. An outlet opening extension extends a distance from the bottom surface of the lid. The outlet opening extension has an inner diameter. A guide pin extends from the bottom surface of the lid. The floating structure is within the housing. The floating structure comprises a float having a top surface and volume. The volume is configured to displace a predetermined volume of liquid so that the top surface of the float remains a depth below a surface of the liquid. An outlet channel extends from the top surface of the float. The outlet channel fits within the inner diameter of the outlet opening extension of the lid. A baffle having a top surface and a bottom surface defining a thickness of the baffle is positioned along a length of the outlet channel to create a saturation zone between the bottom surface of the baffle and the surface of the liquid. At least one opening is in the outlet channel between the top surface of the float and the bottom surface of the baffle. A guide pin sleeve has a complementary shape to the guide pin extends from the top surface of the baffle. The guide pin sleeve is configured to maintain alignment of the floating structure during use. The volume of the float is in fluid communication with the outlet channel and internal walls extend from the top of the float within the outlet channel to a height above the baffle.
Further embodiments of the disclosure are directed to ampoules comprising a housing, a lid, and a floating structure. The housing has a sidewall and a bottom. The lid is positioned on a top surface of the sidewall and has an inlet opening and an outlet opening. The floating structure is within the housing. The float has a top surface and a volume configured to displace a predetermined volume of liquid so that the top surface of the float remains a depth below a surface of the liquid. An outlet channel extends from a top surface of the float. The baffle has an inner portion and an outer portion. The outer portion extends parallel to the top surface of the float. The inner portion extends from the outer portion toward the lid. The baffle is positioned along a length of the outlet channel to create a saturation zone between the bottom surface of the baffle and the surface of the liquid. At least one opening is in the outlet channel between the top surface of the float and the bottom surface of the baffle.
So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments.
Before describing several exemplary embodiments of the disclosure, it is to be understood that the disclosure is not limited to the details of construction or process steps set forth in the following description. The disclosure is capable of other embodiments and of being practiced or being carried out in various ways.
As used in this specification and appended claims, use of relative terms like “above” and “below” should not be taken as limiting the scope of the disclosure to a physical orientation in space. Accordingly, use of relative terms should not be limited to the direction specified by gravity.
Embodiments of the disclosure provide apparatus and methods that provide consistent precursor saturation with varying liquid chemistry height. Some embodiments employ the use of a displaced volume that matches the buoyancy of the ampoule chemistry. One or more embodiments have a flow zone that promotes the saturation of carrier gas with ampoule chemistry. In one or more embodiments, the saturation zone geometric configuration remains the same with changing liquid heights.
Some embodiments of the disclosure reduce the impact of output dose variation due the changing height of ampoule liquid chemistry. Liquid level heights are lowered when chemistry is consumed, and some ampoule applications also have an automated refill capability where fluid heights are raised. One or more embodiments provide a constant saturation zone where incoming carrier gas flows across the liquid chemistry that does not change with overall ampoule liquid heights because the flow structure floats with the surface. Some embodiments incorporate a structure that floats with the liquid surface to maintain constant headspace and constant saturation zone volume.
Some embodiments advantageously provide chemistry ampoules that enable delivery of a constant concentration of saturated gas. Some embodiments advantageously provide apparatus and/or methods that enable a repeatable dose of chemistry to be delivered to deposition chambers and onto the semiconductor wafer surface. Some embodiments provide repeatable deposition rates from wafer to wafer and tool to tool.
Referring to
The ampoule 100 includes a housing 110 having sidewall 112 and a bottom 116. The illustrated ampoule 100 is a generally cylindrically shaped component having one sidewall. Embodiments having different shapes may have more than one sidewall and are within the scope of the disclosure. The sidewall 112 has an inner surface 113 with an inner diameter and an outer surface 114 with an outer diameter. The bottom 116 has an inner face 117 and an outer face 118.
A lid 130 is positioned on a top surface 115 of the sidewall 112. In some embodiments, an O-ring 121 is positioned between the top surface 115 of the sidewall 112 and the lid 130 to maintain a sealed environment within the interior 119 of the ampoule 100. In some embodiments, the O-ring 121 is positioned within a groove 123 formed in the top surface 115 of the sidewall 112, or in the bottom surface 131 of the lid 130. The lid 130 has an inlet opening 132 that extends through the thickness of the lid 130. The lid 130 also has an outlet opening 134 that extends through the thickness of the lid 130.
With reference to
The volume 168 (including the top wall 162, bottom wall 164 and sidewall 166) is configured to displace a predetermined volume of liquid so that the top surface 163 of the top wall 162 of the float 160 remains a depth D below the surface 181 of a liquid 180 within the ampoule 100. The volume that the float 160 occupies depends on the thickness and overall size of the walls and the size of the volume 168. In some embodiments, the float 160 remains a substantially uniform depth D below the surface 181 of the liquid 180 as the overall volume of the liquid 180 changes. For example, the embodiment illustrated in
The float 160 includes an outlet channel 184 that extends from the top surface 163 of the top wall 162. The outlet channel 184 is aligned with the outlet opening 134 of the lid 130.
The float 160 of some embodiments includes an upper volume 168a, as shown in
At least one opening 190 is formed in the outlet channel 184 between the top surface 163 of the float 160 and the bottom surface 172 of the baffle 170. In some embodiments when there are multiple openings 190, the openings 190 are equally spaced around the periphery of the outlet channel 184. In some embodiments, the volume of the openings 190 vary with location on the around the outlet channel 184 to balance gas conductance from the inlet 132. For example, the openings 190 on the same side of the outlet channel 184 as the inlet 132 in some embodiments are smaller than the openings 190 on the opposite side of the outlet channel 184 from the inlet 132 to account for the different distances that a gas has to travel from the inlet 132 to the individual openings 190. In some embodiments, the openings 190 in the outlet channel 184 are sized to provide flow restriction on a side of the outlet channel 184 opposite the inlet 132 in the lid 130.
The size of the baffle 170 is configured so that an outer peripheral edge 174 of the baffle 170 is spaced a distance DB from the inner surface 113 of the sidewall 112 of the housing 110. In some embodiments, the distance DB is in the range of ¼ inch to 1 inch.
The size of the float 160 is configured so that an outer peripheral face 169 of the float 160 is spaced a distance DF from the inner surface 113 of the sidewall 112 of the housing 110. In some embodiments, the distance DF is in the range of ¼ inch to 1 inch.
With reference to
In the illustrated embodiment, the outlet opening 134 extends along a multi-leg pathway through the thickness TL of the lid 130. The illustrated multi-leg pathway forms an opening in the bottom surface 131 of the lid 130 at the approximate center of the lid 130 mass with an opening in the top surface 133 near the periphery of the lid 130 mass. The multi-leg pathway illustrated has a central vertical section forming an opening in the bottom surface 131 of the lid 130, an outer vertical section forming an opening in the top surface 133 of the lid 130 and a horizontal section connecting the two vertical sections.
In some embodiments of the lid 130 further comprises an outlet opening extension 136. The outlet opening extension 136 extends a distance DE from the bottom surface 131 of the lid 130. The outlet opening extension 136 has an inner surface 136i with an inner diameter and an outer surface 136o with an outer diameter forming a wall thickness TWE of the outlet opening extension 136. The distance DE that the outlet opening extension 136 extends from the bottom surface 131 of the lid 130 can vary depending on, for example, the depth of the housing 110 and the length of the outlet channel 184 of the floating structure 150.
Referring again to
The embodiments illustrated in
Referring back to
In some embodiments, the lid 130 further comprises a guide pin 210 extending from the bottom surface 131 of the lid 130. The guide pin 210 illustrated is a cylindrical shaped protrusion from the bottom surface 131 of the lid 130. However, the skilled artisan will recognize that this is merely one possible configuration and should not be taken as limiting the scope of the disclosure. The shape of the guide pin 210 can be any suitable shape including, but not limited to, those shapes having square, rectangular, triangular, pentagonal cross-sections (e.g., triangular prisms, rectangular prisms, etc.).
In some embodiments, the baffle 170 further comprises a guide pin sleeve 215. The guide pin sleeve 215 has a complementary shape to the guide pin 210 so that the guide pin sleeve 215 can slide along the length of the guide pin 210 during vertical movement of the floating structure 150. The guide pin sleeve 215 is configured to maintain alignment of the floating structure during vertical movement of the floating structure 150 during use of the ampoule so that as the floating structure moves vertically within the housing 110, the orientation of the floating structure 150 remains substantially the same. In some embodiments, as shown in
In the illustrated embodiments, the guide pin 210 is connected to the lid 130 and the guide pin sleeve 215 is connected to the baffle 170. However, the skilled artisan will recognize that this is merely one possible configuration of these complementary components and that other arrangements are within the scope of the disclosure. In some embodiments, this configuration is reversed so that the guide pin 210 is connected to the baffle 170 and the guide pin sleeve 215 is connected to the lid 130.
Referring to
Referring to
In the illustrated embodiment, the inner portion 250 of the baffle 170 is substantially parallel to the outlet channel 184. However, the skilled artisan will recognize that this is merely representative of one possible configuration and does not limit the disclosure to such an arrangement. In some embodiments, the inner portion 250 is angled relative to the outlet channel 184 so that the inner portion 250 slopes toward the outer portion 260 so that the gap 255 is narrower near the lid 130 than near the outer portion 260.
In some embodiments, as shown in
Reference throughout this specification to “one embodiment,” “certain embodiments,” “various embodiments,” “one or more embodiments” or “an embodiment” means that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. Thus, the appearances of the phrases such as “in one or more embodiments,” “in certain embodiments,” “in various embodiments,” “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily referring to the same embodiment of the disclosure. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments.
Although the disclosure herein provided a description with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made to the present disclosure without departing from the spirit and scope thereof. Thus, it is intended that the present disclosure include modifications and variations that are within the scope of the appended claims and their equivalents.
