Focused ion beam mask maker

Claim 2

In a method of making a pattern on a photolithographic mask for semiconductor devices wherein the mask has a metallic coating on a surface of a transparent substrate, the improvement comprising: using a field ion source to produce a beam of ions; accelerating the ions; and directly bombarding the metallic coating on the mask substrate with the accelerated ions to form openings in the coating in a desired pattern.

Claim 3

The method of claim 1 wherein the field ion source produces an ion beam having a current of at least 1 × 10 -10 amperes.

Claim 4

The method of claim 2 which further includes the step of focusing the ion beam to produce a spot size on the coating of less than 5000 A in diameter.

Claim 5

In a method of making a pattern on a photolithographic mask wherein the mask has a metallic coating on a surface of a transparent substrate, the improvement comprising: introducing xenon gas into the chamber of a field ion source including a needle anode having a tip with a radius of less than 5000 A; ionizing the gas as it passes over the tip of said needle anode to produce xenon ions; accelerating the ions; focussing the ions into a beam having a spot size of less than 1000 A in diameter at the metallic coating; and bombarding the metallic coating of the mask with the accelerated ion beam to selectively remove the metal to form openings therein in a desired pattern.

Claim 6

In a method of making a pattern on a photolithographic mask wherein the mask has a metallic coating on a surface of a transparent substrate, the improvement comprising: introducing xenon gas into the chamber of a field ion source including a needle anode having a tip with a radius of less than 5000 A; ionizing the gas as it passes over the tip of said needle anode to produce xenon ions; accelerating the ions; focussing the ions into a beam having a spot size of less than 1000 A in diameter at the metallic coating; and bombarding the metallic coating of the mask with the accelerated ion beam to selectively remove the metal to form openings therein in a desired pattern.

Claim 7

The method of claim 4 wherein the field ion source produces a current of at least 1 × 10 -10 amperes.

Claim 8

The method of claim 5 wherein the needle anode is at a positive potential of between 10-30 kilovolts with respect to said metallic coating.

Claim 9

The method of claim 6 wherein the metallic coating is gold.

Claim 10

In a method of making a pattern on a photolithographic mask for semiconductor devices wherein the mask has a metallic coating on a surface of a transparent substrate, the improvement comprising: feeding liquidified gallium to the tip of a needle anode in a field ion source; ionizing the liquid as it reaches the tip of said needle anode to produce gallium ions; accelerating the ions; focussing the ions into a beam having a spot size of less than 1000 A in diameter at the metallic coating; and bombarding the metallic coating of the mask with the accelerated ion beam to selectively remove the metal to form openings therein in a desired pattern.

Claim 11

In a method of making a pattern on a photolithographic mask for semiconductor devices wherein the mask has a metallic coating on a surface of a transparent substrate, the improvement comprising: feeding liquidified gallium to the tip of a needle anode in a field ion source; ionizing the liquid as it reaches the tip of said needle anode to produce gallium ions; accelerating the ions; focussing the ions into a beam having a spot size of less than 1000 A in diameter at the metallic coating; and bombarding the metallic coating of the mask with the accelerated ion beam to selectively remove the metal to form openings therein in a desired pattern.

Claim 12

The method of claim 8 wherein the field ion source produces a current of at least 1 × 10 -10 amperes.

Claim 13

The method of claim 9 wherein the liquid gallium is fed through a bore in the needle anode, and wherein the tip of the needle anode has a radius of less than 5000 A.

Claim 14

In a method of making a pattern on semiconductor devices wherein such devices have a coating on a surface of a substrate, the improvement comprising: using a field ion source to produce a beam of ions; accelerating the ions; and directly bombarding the coating on the substrate with the accelerated ions to form openings in the coating in a desired pattern.

Claim 15

In a method of making a pattern on semiconductor devices wherein such devices have a coating on a surface of a substrate, the improvement comprising: using a field ion source to produce a beam of ions; accelerating the ions; and directly bombarding the coating on the substrate with the accelerated ions to form openings in the coating in a desired pattern.

Claim 16

The method of claim 11 wherein the field ion source produces an ion beam having a current of at least 1 × 10 -10 amperes.

Claim 17

The method of claim 12 which further includes the step of focusing the ion beam to produce a spot size on the coating of less than 5000 A in diameter.

Claim 18

In a method of making a pattern on a device which has a coating on a surface of a substrate, the improvement comprising: introducing xenon gas into the chamber of a field ion source including a needle anode having a tip with a radius of less than 5000 A; ionizing the gas as it passes over the tip of said needle anode to produce xenon ions; accelerating the ions; focussing the ions into a beam having a spot size of less than 1000 A in diameter at the coating; and bombarding the coating of the substrate with the accelerated ion beam to selectively remove the coating to form openings therein in a desired pattern.

Claim 19

In a method of making a pattern on a device which has a coating on a surface of a substrate, the improvement comprising: introducing xenon gas into the chamber of a field ion source including a needle anode having a tip with a radius of less than 5000 A; ionizing the gas as it passes over the tip of said needle anode to produce xenon ions; accelerating the ions; focussing the ions into a beam having a spot size of less than 1000 A in diameter at the coating; and bombarding the coating of the substrate with the accelerated ion beam to selectively remove the coating to form openings therein in a desired pattern.

Claim 20

The method of claim 14 wherein the field ion source produces a current of at least 1 × 10 -10 amperes.

Claim 21

The method of claim 15 wherein the needle anode is at a positive potential of between 10-30 kilovolts with respect to said metallic coating.

Claim 22

The method of claim 16 wherein the coating is gold.

Claim 23

In a method of making a pattern on semiconductor devices wherein such devices have a coating on a surface of a substrate, the improvement comprising: feeding liquidified gallium to the tip of a needle anode in a field ion source; ionizing the liquid as it reaches the tip of said needle anode to produce gallium ions; accelerating the ions; focussing the ions into a beam having a spot size of less than 1000 A in diameter at the coating; and bombarding the coating of the substrate with the accelerated ion beam to selectively remove the coating to form openings therein in a desired pattern.

Claim 24

In a method of making a pattern on semiconductor devices wherein such devices have a coating on a surface of a substrate, the improvement comprising: feeding liquidified gallium to the tip of a needle anode in a field ion source; ionizing the liquid as it reaches the tip of said needle anode to produce gallium ions; accelerating the ions; focussing the ions into a beam having a spot size of less than 1000 A in diameter at the coating; and bombarding the coating of the substrate with the accelerated ion beam to selectively remove the coating to form openings therein in a desired pattern.

Claim 25

The method of claim 18 wherein the field ion source produces a current of at least 1 × 10 -10 amperes.

Claim 26

The method of claim 19 wherein the liquid gallium is fed through a bore in the needle anode, and wherein the top of the needle anode has a radius of less than 5000 A.