# US 2021/0243850 A1 · Ceramic heater

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- Number: US 2021/0243850 A1
- Document ID: US20210243850A1
- Status: Published application
- Kind: A1
- Application number: 17/301,992
- Filed: 2021-04-21
- Published: 2021-08-05
- Earliest claimed: 2019-01-25
- Assignees: NGK Insulators, Ltd.
- Applicants: Ngk Insulators, Ltd.
- Inventors: Masaki ISHIKAWA; Shuichiro MOTOYAMA
- Web page: https://patentgrep.com/patent/US20210243850A1

## CPC

- H05B 3/265: {the insulating base being an inorganic material, e.g. ceramic (H05B3/262 takes precedence)}
- H05B 3/283: {the insulating material being an inorganic material, e.g. ceramic}
- H10P 72/0432: {mainly by conduction}
- H10P 95/00: Generic processes or apparatus for manufacture or treatments not covered by the other groups of this subclass
- H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

A ceramic heater includes a ceramic plate, a main resistance heating element, and sub resistance heating elements. The main resistance heating element is a heating element that is disposed on a first plane parallel with a wafer placement surface in the ceramic plate and that has a coil shape. The sub resistance heating elements are heating elements that are disposed on a second plane parallel with the first plane in the ceramic plate between the first plane and the wafer placement surface, that complement heating with the main resistance heating element, and that have a two-dimensional shape.

## Claims

### Claim 1

A ceramic heater comprising:
a ceramic plate that has a wafer placement surface;
a main resistance heating element that is disposed on a first plane parallel with the wafer placement surface in the ceramic plate and that has a coil shape; and
a sub resistance heating element that is disposed on a second plane parallel with the first plane in the ceramic plate, that complements heating with the main resistance heating element, and that has a two-dimensional shape.

### Claim 2 (depends on 1)

The ceramic heater according to claim 1,
wherein the second plane is located between the first plane and the wafer placement surface.

### Claim 3 (depends on 1)

The ceramic heater according to claim 1,
wherein the sub resistance heating element contains ceramics.

### Claim 4 (depends on 1)

The ceramic heater according to claim 1,
wherein the main resistance heating element is disposed in m (m is an integer of 1 or more) zones on the first plane respectively, and
wherein the sub resistance heating element is disposed in n (n is an integer larger than m) zones on the second plane respectively.

### Claim 5 (depends on 1)

The ceramic heater according to claim 1,
wherein the sub resistance heating element is divided into sectorial shapes.

### Claim 6 (depends on 1)

The ceramic heater according to claim 1,
wherein the sub resistance heating element is nearer than the main resistance heating element to a hole.

### Claim 7 (depends on 1)

The ceramic heater according to claim 1,
wherein the sub resistance heating element overlaps a terminal of the main resistance heating element in a plan view of the wafer placement surface.