SINTERED YTTRIUM OXIDE BODY OF LARGE DIMENSION
Disclosed herein is a sintered yttrium oxide body having a total impurity level of 40 ppm or less, a density of not less than 4.93 g/cm3, wherein the sintered yttrium oxide body has at least one grain boundary comprising silica in an amount of not less than 1 to not greater than 10 atoms/nm2 wherein the sintered yttrium oxide body has at least one surface comprising at least one pore, wherein no pore is larger than 5 μm in diameter. A process for making the sintered yttrium oxide body is also disclosed.
1 - 114 . (canceled)
115 . A sintered yttrium oxide body having a total impurity level of 40 ppm or less, a density of not less than 4.98 g/cm 3 , wherein the sintered yttrium oxide body has at least one grain boundary comprising silica in an amount of not less than 1 to not greater than 10 atoms/nm 2 wherein the sintered yttrium oxide body has at least one surface comprising at least one pore, wherein no pore is larger than 5 μm in diameter.
116 . The sintered yttrium oxide body of claim 115 , wherein no pore is larger than 4 μm in diameter.
117 . The sintered yttrium oxide body of claim 115 wherein the total impurity level is 35 ppm or less.
118 . The sintered yttrium oxide body of claim 115 having a pore size distribution with a maximum pore size of 1.50 μm for 95% or more of all pores on the at least one surface.
119 . The sintered yttrium oxide body of claim 115 wherein the at least one surface has an area of which less than 0.15% is occupied by pores.
120 . The sintered yttrium oxide body of claim 115 having at least one dimension of from 100 mm to 600 mm.
121 . The sintered yttrium oxide body of claim 115 wherein the density does not vary by more than 3% along the at least one dimension.
122 . A process of making a sintered yttrium oxide body, the process comprising the steps of:
a. disposing yttrium oxide powder inside an inner volume defined by a spark plasma sintering tool, wherein the spark plasma sintering tool comprises: a die comprising a sidewall comprising an inner wall and an outer wall, wherein the inner wall has a diameter that defines the inner volume; an upper punch and a lower punch operably coupled with the die, wherein each of the upper punch and the lower punch have an outer diameter that is less than the diameter of the inner wall of the die thereby creating a gap between each of the upper punch and the lower punch and the inner wall of the die when at least one of the upper punch and the lower punch are moved within the inner volume of the die, wherein the gap is from 10 μm to 70 μm wide and creating vacuum conditions inside the inner volume;
b. applying a pressure of from 10 MPa to 60 MPa to the yttrium oxide powder by moving at least one of the upper punch and the lower punch within the inner volume of the die to apply pressure to the yttrium oxide powder while heating to a sintering temperature of from 1200 to 1600° C. and performing sintering to form a sintered yttrium oxide body; and
c. lowering the temperature of the sintered yttrium oxide body, wherein the yttrium oxide powder of step a) has a surface area of 10 m 2 /g or less, wherein the sintered yttrium oxide body has a total impurity level of 40 ppm or less, a density of not less than 4.98 g/cm 3 , at least one surface comprising at least one pore, wherein no pore is larger than 5 μm in diameter.
123 . The process of claim 122 , further comprising the steps of:
d. optionally annealing the sintered yttrium oxide body by applying heat to raise the temperature of the sintered yttrium oxide body to reach an annealing temperature, performing annealing;
e. lowering the temperature of the annealed sintered yttrium oxide body to an ambient temperature by removing the heat source applied to the sintered yttrium oxide body; and
f. optionally machining the annealed sintered yttrium oxide body to create a sintered yttrium oxide body component, wherein the component is selected from the group consisting of a dielectric window or RF window, a focus ring, a nozzle or a gas injector, a shower head, a gas distribution plate, an etch chamber liner, a plasma source adapter, a gas inlet adapter, a diffuser, an electronic wafer chuck, a chuck, a puck, a mixing manifold, an ion suppressor element, a faceplate, an isolator, a spacer, and a protective ring.
124 . The process as in any one of claims 122 wherein the yttrium oxide powder is calcined prior to step a).
125 . The process as in any one of claims 122 wherein the yttrium oxide powder has a surface area of from 1.5 to 7.0 m 2 /g.
126 . The process as in claim 122 wherein the sintering is performed for a time of from 1 minute to 120 minutes.
127 . The process as in claim 122 wherein no pore on the at least one surface is larger than 4 μm in diameter.
128 . The process as in claim 122 wherein the total impurity level of the sintered yttrium oxide body is 35 ppm or less.
129 . The process as in claim 122 wherein the sintered yttrium oxide body has at least one dimension of from 100 mm to 600 mm.