Deposition of TiN films in a batch reactor

• US 7,966,969 B2
• Filed: 03/31/2005
• Issued: 06/28/2011
• Est. Priority Date: 09/22/2004
• Status: Active Grant

• Current Assignee: ASM IP Holding B.V. (ASM International NV)
• Original Assignee: ASM International NV
• Inventors: Vandezande, Lieve, Bankras, Radko Gerard, Snijders, Gert-Jan, Hasper, Albert, De Blank, Marinus J.
• Primary Examiner(s): LUND, JEFFRIE ROBERT
• Application Number:
  US11/096,861
• Publication Number:
  US 20060060137A1
• Time in Patent Office: 2,280 Days
• Field of Search: 118/715, 118/724, 118/725, 118/696, 118/697, 432/241
• US Class Current: 118/697
• CPC Class Codes: C23C 16/34 Nitrides C23C16/303 takes precedence
• CPC Class Codes: C23C 16/45527 characterized by the ALD cycle, e.g. different flows or temperatures during half-reactions, unusual pulsing sequence, use of precursor mixtures or auxiliary reactants or activations
• CPC Class Codes: C23C 16/45546 specially adapted for a substrate stack in the ALD reactor
• CPC Class Codes: H01L 21/28556 by chemical means, e.g. CVD, LPCVD, PECVD, laser CVD H01L21/28518 - H01L21/28537 and H01L21/28568 take precedence
• CPC Class Codes: H01L 21/28562 Selective deposition

Abstract

Titanium nitride (TiN) films are formed in a batch reactor using titanium chloride (TiCl₄) and ammonia (NH₃) as precursors. The TiCl₄ is flowed into the reactor in temporally separated pulses. The NH₃ can also be flowed into the reactor in temporally spaced pulses which alternate with the TiCl₄ pulses, or the NH₃ can be flowed continuously into the reactor while the TiCl₄ is introduced in pulses. The resulting TiN films exhibit low resistivity and good uniformity.

Claims

1. A batch reactor, comprising:

a vertically extending reaction chamber configured to accommodate a plurality of vertically spaced semiconductor substrates, the chamber having a top end and a bottom end;

a purge gas injector accommodated inside the chamber, wherein the purge gas injector extends upwardly from proximate the bottom end of the reactor and has an opening to the reaction chamber proximate the top end of reaction chamber, wherein the purge gas injector is connected to a feed for purge gas and is configured to expel substantially all purge gas flowing through the purge gas injector out of the opening;

a titanium precursor gas injector and a nitrogen precursor gas injector accommodated in the reaction chamber, the titanium precursor and nitrogen precursor gas injectors extending substantially a height of the chamber and connected to a process gas delivery system, the process gas delivery system configured to deliver titanium and nitrogen precursor gases to the reaction chamber, each precursor gas through a different one of the gas injectors;

a controller programmed to perform a plurality of titanium nitride chemical vapor deposition cycles, each chemical vapor deposition cycle performed at a deposition temperature of less than about 500°

C. and comprising the steps of;

a. exposing the plurality of substrates to the titanium and nitrogen precursors by flowing a pulse of the titanium precursor into the reaction chamber simultaneously with flowing the nitrogen precursor into the reaction chamber;

b. after step a, stopping a flow of the titanium precursor into the reaction chamber; and

c. while the flow of the titanium precursor is stopped, exposing the plurality of substrates to the nitrogen precursor by flowing the nitrogen precursor into the reaction chamber at an increased flow rate relative to a flow rate of the nitrogen precursor into the reaction chamber during step a,

wherein titanium nitride films formed by performing the plurality of chemical vapor deposition cycles have resistivities that vary by less than about 5 μ

Ohm·

cm from substrate to substrate within the plurality of substrates; and

a gas exhaust proximate the bottom end of the reaction chamber.

2. The batch reactor of claim 1, wherein the purge gas injector only opens proximate a top of the reaction chamber.

3. The batch reactor of claim 1, wherein the reaction chamber has a closed top end and a bottom end which can be opened for introduction of the substrates.

4. The batch reactor of claim 1, wherein the nitrogen precursor gas injector is a multiple hole injector having a plurality of vertically spaced-apart holes for discharging gas into the reaction chamber in a vertically distributed manner.

5. The batch reactor of claim 4, wherein the nitrogen precursor gas injector is in gas communication with a source of NH₃ and wherein the gas delivery system is configured to deliver NH₃ through the nitrogen precursor gas injector.

6. The batch reactor of claim 5, wherein the titanium precursor gas injectoris in gas communication to a source of TiCI₄.

7. The batch reactor of claim 6, wherein the titanium precursor gas injector is a multiple hole injector having a plurality of vertically spaced-apart holes to discharge gas into the reaction chamber in a vertically distributed manner.

8. The batch reactor of claim 1, wherein the reaction chamber is configured to accommodate 25 or more substrates.

9. The batch reactor of claim 8, wherein the reaction chamber is configured to accommodate 50 or more substrates.

10. The batch reactor of claim 9, wherein the reaction chamber is configured to accommodate 100 or more substrates.