JP-WO2025062583-A5 -

Dates

Publication Date

20260507

Application Date

20230921

Description

To solve the above problems, a first aspect of the present invention is a wafer mounting stand on which a wafer is placed and fixed, comprising: a ceramic substrate having a wafer mounting surface; an electrostatic chuck equipped with an ESC electrode and a heater electrode, each embedded inside the ceramic substrate; a metal cooling plate; and a resin adhesive sheet sandwiched between the electrostatic chuck and the cooling plate to bond the electrostatic chuck and the cooling plate, wherein the adhesive surface of the electrostatic chuck to the adhesive sheet has an uneven structure consisting of one or more types of unit structures, the uneven structure has protrusions provided at a pitch of 100 μm to 300 μm , and the adhesive surface includes the tip surfaces of the protrusions . A third aspect of the present invention is a wafer mounting stage according to the first aspect, characterized in that the adhesive surface of the electrostatic chuck has the plurality of types of unit structures, and the distance between the tip of the protrusion and the cooling plate is different for each of the plurality of types of unit structures . A fifth aspect of the present invention is a wafer mounting stand according to the fourth aspect, wherein the adhesive surface of the electrostatic chuck consists of a plurality of unit regions, the plurality of unit structures consist of a first unit structure having a first convex portion forming the convex portion and a second unit structure having a second convex portion forming the convex portion, the distance between the tip of the first convex portion and the cooling plate and the distance between the tip of the second convex portion and the cooling plate are different, the first unit structure and the second unit structure are mixed in each of the plurality of unit regions in a predetermined ratio, and the predetermined ratio in each of the plurality of unit regions is determined according to the reference temperature distribution that occurs on the mounting surface when current is applied to the heater electrode of the wafer mounting stand which is flat, the adhesive surface of the electrostatic chuck. A seventh aspect of the present invention is a method for manufacturing a wafer mounting stand on which a wafer is mounted and fixed, comprising: a preparation step of preparing an electrostatic chuck comprising a ceramic substrate having a wafer mounting surface and an ESC electrode and a heater electrode, each embedded inside the ceramic substrate; and an bonding step of bonding the electrostatic chuck and a metal cooling plate with a resin adhesive sheet sandwiched between them , wherein the preparation step includes a correction step of providing an uneven structure by alternately and periodically providing convex and concave portions on the bonding surface of the electrostatic chuck to the adhesive sheet, and the correction step is at least one of a first correction step of reducing variations in the temperature distribution occurring on the mounting surface and a second correction step of absorbing thickness variations in the adhesive sheet in the concave portions , wherein in the bonding step, the tip surfaces of the convex portions are included in the bonding surface . The adhesive sheet 40 is an adhesive sheet made of a resin such as a thermosetting epoxy resin. The bonding of the electrostatic chuck 20 and the cooling plate 30 using the adhesive sheet 40 is achieved, for example, by performing a heat-pressure bonding in which a laminate in which the adhesive sheet 40 is sandwiched between the electrostatic chuck 20 and the cooling plate 30 is heated and pressurized at a predetermined temperature. The thickness of the adhesive sheet 40 is preferably at least 100 μm to 300 μm before bonding. Furthermore, the mounting surface 20a of the electrostatic chuck 20 after hot pressing may be embossed (recessed) to provide numerous protrusions (projections). Therefore, from a macroscopic perspective, the bonding of the electrostatic chuck 20 having an uneven structure 25 to the cooling plate 30 using an adhesive sheet 40 according to this embodiment is substantially equivalent to bonding the electrostatic chuck 20 and the cooling plate 30 using an adhesive sheet 40, where the adhesive surface is a flat surface corresponding to the uneven reference line L, and the chuck 20 does not have such an uneven structure 25. On the other hand, in the wafer mounting table 10 according to this embodiment, the contact area between the electrostatic chuck 20 and the adhesive sheet 40 is increased compared to the case where a flat surface without the uneven structure 25 is the adhesive surface , and therefore the adhesive strength of the electrostatic chuck 20 is further increased. Furthermore, when heating a wafer placed on the mounting surface 20a, the electrostatic chuck 20 generates heat when power is supplied to the heater electrode 22. This heat is transferred from the electrostatic